Conditions
Conditions are named patterns. Each entry explains what the pattern can reflect, how it is typically investigated, and what approaches exist — without ranking them for you.
Pages are returning one at a time as each is checked again. Those listed here have been checked and signed off again by a veterinary surgeon.
Pain & Mobility
Achilles Mechanism Rupture
Achilles mechanism rupture describes a breakdown in the system of tissues that connects the large muscles at the back of the lower leg to the point of the hock, allowing the dog to bear weight and push off during movement. When this mechanism fails, whether through tendon tear, muscle injury, or separation at the bone, the hock may drop lower than usual, and the dog often cannot place weight normally on that limb. Owners typically notice a sudden or gradual change in how the leg is carried. A sudden change often follows an injury such as a cut or a heavy impact to the back of the leg, while in other dogs the tendon wears down over weeks or months with no known injury. The leg may appear to bend in an unusual way, or the dog may walk with the hock close to or touching the ground. This page explores the patterns that may suggest Achilles mechanism injury, the anatomy and forces involved, how the condition is investigated through examination and imaging, and the range of approaches, both surgical and non-surgical, that exist for managing these injuries.
Achilles Tendon Injury
The common calcaneal tendon, often called the Achilles tendon, is a structure formed from several muscle tendons in the back of the hind leg that attach to the calcaneus, the bone at the point of the hock. When this tendon is torn, ruptured, or strained, the hock tends to drop towards the ground and the leg loses much of its normal push-off strength. Owners often notice a sudden change in how the leg is carried, sometimes after a known injury but sometimes with no clear cause. Injury to this tendon can occur through a wound that cuts it, through sudden overstretching during activity, or through gradual weakening over time. The way it presents varies with the type and extent of damage: a partial strain may cause only mild lameness and some thickening, while a complete rupture often produces a distinctive flat-footed stance. This page explores what an owner may observe at home, what is happening within the tendon and surrounding structures, how the injury is investigated through examination and imaging, and the range of approaches that exist, from rest and immobilisation through to surgical repair, each with its own profile of recovery and outcome.
Anal Sac Impaction
Anal sac impaction occurs when the small scent glands located on either side of a dog's or cat's anus become filled with fluid that does not empty naturally. These glands typically release a small amount of material during defaecation, but when the ducts become blocked or the fluid thickens, the sacs can become overfull and uncomfortable. The condition is more common in smaller dogs, though it can affect any breed or size. Owners most often notice scooting, dragging the bottom along the ground, or excessive licking around the tail base. Some animals may chase their tail, have difficulty settling, or show discomfort when sitting. The area may appear swollen or red, and there may be a strong, unpleasant odour. These signs can also overlap with other conditions affecting the same region, so the pattern observed at home is part of a broader picture. This page explores the signals that may suggest impaction, what leads the glands to overfill or fail to empty, how the condition is identified during examination, and the range of approaches used to manage it, from manual expression to dietary adjustment and, in some cases, surgical removal of the glands.
Angular Limb Deformity
Angular limb deformity describes a condition in which one or more of a young dog's leg bones grow unevenly, causing the limb to bend or twist in a way that changes its alignment. This typically becomes visible during the months of rapid growth, most often in the foreleg, and can range from subtle changes in how the paw sits to more pronounced bowing or rotation of the limb. The underlying issue is usually an imbalance in growth between two paired bones, most commonly the radius and ulna in the foreleg, where one bone grows more slowly or stops growing earlier than the other. Owners often notice that a puppy's front leg appears curved, that the paw turns outward or inward, or that the dog shifts weight in an unusual way. In some cases the change develops gradually and is first seen as an awkward gait or a difference in leg shape compared to the other side. The condition is more common, and tends to be more complex, in chondrodystrophic breeds such as the Dachshund and Basset Hound, in which an inherited growth pattern predisposes to bowing of the foreleg. It also occurs in larger and giant breeds and in any dog that has had an injury to a growth plate. This page explores the signs that may be observed, what happens within the bone during growth to create the deformity, how the condition is investigated through examination and imaging, and the range of approaches, from monitoring in mild cases to surgical correction in others, that may be considered depending on the degree of deformity, the age of the dog, and the impact on comfort and function.
Arthritis in Cats
A degenerative joint condition that is common in older cats but often goes unrecognised due to subtle behavioural changes.
Atlantoaxial Instability
Atlantoaxial instability describes excessive movement between the first two bones of the neck: the atlas and the axis. In a stable joint, ligaments and the shape of the bones themselves hold these vertebrae in alignment; when that support is absent or insufficient, the bones can shift out of position, and the spinal cord that runs between them may be compressed. The condition is seen most often in young toy-breed dogs, and less commonly in larger dogs and cats, though it can also develop after injury in animals of any size. Owners may notice neck pain, a reluctance to move the head, an unsteady gait, or weakness in one or more limbs. In some animals the signs appear suddenly after minor trauma, such as a jump or a stumble, while in others they build gradually over weeks or months. The severity varies widely; some animals show only discomfort, while others lose the ability to walk. This page explores what might be observed in an affected animal, the anatomical and developmental factors that underlie the instability, how the condition is investigated through imaging, and the range of approaches, both surgical and non-surgical, that exist to address it.
Avascular Necrosis of the Femoral Head
Avascular necrosis of the femoral head is a condition in which the blood supply to the ball of the hip joint is disrupted, causing the bone tissue to die and the joint surface to collapse. It tends to affect young dogs of small and toy breeds, often appearing between four and eleven months of age, and typically involves only one hip. Owners most commonly notice a gradual onset of limping on one hind leg, with the dog becoming reluctant to bear weight or use the affected limb. The lameness may worsen over weeks to months as the bone deteriorates, and the dog may hold the leg up or show discomfort when the hip is moved. This page explores the signals that may be observed, what is happening beneath the surface in the bone and joint, how the condition is investigated through examination and imaging, and the approaches that exist to manage it.
Bicipital Tenosynovitis
Bicipital tenosynovitis describes inflammation affecting the biceps tendon and the sheath that surrounds it as it runs along the front of the shoulder. The biceps tendon plays a role in stabilising the shoulder joint and assisting certain movements of the foreleg, and when the tendon or its protective sheath becomes inflamed, this can lead to discomfort and altered use of the limb. Owners most often notice limping that may be subtle at first, particularly after rest or in the morning, or a reluctance to bear full weight on the affected front leg. The lameness may improve with gentle movement and worsen again after exercise. Some dogs show stiffness when navigating stairs or resist certain movements that involve flexing the shoulder. This page explores the patterns that may raise the possibility of bicipital tenosynovitis, what is understood about the underlying changes in the tendon and surrounding structures, how the condition is investigated through examination and imaging, and the range of conservative and interventional approaches that may be considered depending on severity and response.
Brachycephalic Obstructive Airway Syndrome (BOAS) in Dogs
Brachycephalic obstructive airway syndrome describes a collection of anatomical features in short-nosed dogs that can make breathing more difficult than it is for dogs with longer muzzles. The features often include narrowed nostrils, a soft palate that is too long and too thick, and a narrowed windpipe, though not every dog has all of them. These features are part of the breed shape, but in some individuals they create enough resistance that breathing becomes effortful, particularly during exercise, excitement, or warm weather. Owners often notice noisy breathing, such as snoring, snorting, or honking sounds, especially during activity or sleep. Some dogs tire quickly on walks, overheat more easily than other breeds, or seem to struggle to catch their breath after exertion. Others may gag, retch, or bring up foam, particularly after eating or drinking. The severity varies widely: some dogs live comfortably with these features, while others find daily activities genuinely difficult. This page explores what these features look like from the outside, what is happening in the airways, how the condition is assessed, and the range of approaches, both surgical and supportive, that exist. It also considers how age, weight, and environment can influence the picture over time.
Burns
Burns are injuries to the skin and sometimes deeper tissues caused by heat, chemicals, electricity, or radiation. The damage occurs when the tissue is exposed to something that destroys the protective outer layers and, depending on severity, the structures beneath. What an owner observes often depends on the cause and depth: reddened, darkened or weeping skin after contact with a hot surface, singed fur and raw patches from a fire or boiling liquid, or weeping sores after chemical exposure. The appearance at first encounter varies widely. Some burns look mild at the outset and worsen over the following hours or days as the full extent of tissue damage declares itself. Pain levels, the risk of infection, and the time to healing all depend on how much of the skin's thickness has been affected and how large an area is involved. Large burns, burns from a fire where smoke was breathed in, and injuries from chewing an electrical cable can also affect the whole body, with shock or breathing problems developing over hours to days. This page explores the patterns that prompt concern, the processes occurring in burned tissue, the ways burns are assessed and categorised, and the range of approaches used to support healing and manage discomfort.
Carpal Hyperextension Injury
Carpal hyperextension injury describes damage to the ligaments on the underside of the carpus (the cluster of small bones that forms the 'wrist' of the front leg), allowing the joint to sink or bow downward under weight. The supporting fibrous structures normally hold the carpus in a slight forward angle when the paw is on the ground; when those ligaments tear or stretch beyond recovery, the joint can drop towards or even touch the floor during walking or standing. Owners often notice a sudden change in the way the front leg looks when their dog or cat is moving or bearing weight. The lower leg may appear to collapse partway down, or the back of the wrist and the long bones below it may rest flat against the ground. The change can follow a fall, a jump, or sometimes no remembered event at all. Some dogs and cats develop it without any known injury, and in cats this form often affects both front legs. This page explores the signals that can point towards this injury, the structures involved and how they fail, the ways the problem is investigated, and the approaches used to manage it, including both supportive measures and surgical fusion of the joint, which is the usual surgical treatment when ligament damage is substantial.
Cauda Equina Syndrome
Cauda equina syndrome describes a pattern that occurs when the bundle of nerves at the base of the spine (the cauda equina) comes under pressure. These nerves carry signals to and from the hind legs, tail, bladder, and bowel, so pressure in this area can affect movement, sensation, and control in all of these regions. The condition tends to develop in medium to large dogs, with signs most often starting between three and seven years of age, and can appear gradually or quite suddenly. Owners often notice reluctance to jump, difficulty rising, a change in tail carriage, or hesitation on stairs. Some dogs become quieter on walks, sit down frequently, or seem uncomfortable when touched near the base of the tail. In other cases, the first sign may be a subtle loss of coordination in the hind legs, or changes in toileting behaviour that are harder to interpret at first. This page explores the signals that may prompt concern, what is happening in the spine to cause those signals, how the condition is investigated, and the range of approaches (medical and surgical) that exist. The aim is to help you understand the shape of the condition and the conversations that may follow.
Caudal Cruciate Ligament Injury
The caudal cruciate ligament is one of two major ligaments that cross inside the stifle (knee) joint, running from the back of the tibia up to the front of the femur. When this ligament is injured or torn, the tibia can shift abnormally backward in relation to the femur, and the joint may feel unstable or painful during movement. Lameness ranges from mild to not bearing weight on the leg at all. Some dogs show a subtle lameness that comes and goes, reluctance to bear full weight on the affected leg, or stiffness after rest. Caudal cruciate injury is much less common than injury to the cranial cruciate ligament, and it often occurs alongside other joint trauma (a fall, a road traffic accident or a collision), though it can occasionally happen in isolation. This page explores the signs that may be observed, what happens inside the joint when the ligament is damaged, how the injury is investigated through examination and imaging, and the range of approaches that exist, from rest and controlled activity through to surgical stabilisation in cases where lameness persists, the joint remains unstable or other stifle ligaments are also torn.
Cherry Eye
Cherry eye is the common name for a condition in which a tear gland that normally sits tucked out of sight in the corner of the eye becomes displaced and visible as a pink or red swelling. This gland, the third eyelid gland, produces a significant portion of the tear film, and when it moves out of position, it can no longer do that job as effectively. The appearance can be sudden, often noticed as a smooth, rounded lump in the inner corner of one or both eyes. Owners often describe the swelling as looking like a small bean or a piece of red tissue that wasn't there before. It may come and go at first, or it may remain visible. Some dogs seem unbothered; others may paw at the eye or squint if the exposed tissue becomes dry or irritated. The condition is seen more often in certain breeds, particularly younger dogs, and can affect one eye or both, and the second eye may follow later. This page explores what may be observed, what is happening beneath the surface, how the condition is identified, and the range of approaches that exist, each with its own profile of outcomes, tradeoffs, and considerations over time.
Coxofemoral Subluxation
Coxofemoral subluxation describes a partial displacement of the hip joint, where the head of the femur (thighbone) shifts out of its normal position within the acetabulum (hip socket) but remains in some contact with it. This can happen suddenly after trauma, or develop gradually in dogs or cats with underlying hip joint problems. The hip may slip in and out of place, or sit in a persistently abnormal position. Owners often notice a sudden onset of limping or difficulty bearing weight on one hind leg, particularly after a fall, collision, or awkward movement. In some cases, the leg may appear shorter or held at an unusual angle, and the animal may be reluctant to move or show discomfort when the hip is handled. Where the subluxation develops more slowly, signs may be subtler: intermittent lameness, stiffness after rest, or a change in gait that comes and goes. This page explores the signs that can accompany hip subluxation, what may be happening within and around the joint, how the condition is investigated through examination and imaging, and the range of approaches that may be considered depending on the individual case, from rest and physiotherapy to surgical stabilisation.
Cruciate Ligament Disease in Cats
Cruciate ligament disease in cats involves damage to one of the stabilising bands of tissue inside the knee joint. The cranial cruciate ligament, the one usually affected, normally stops the shin bone sliding forward relative to the thigh bone during movement. The caudal cruciate ligament stops it sliding backward. When a cruciate ligament is weakened or torn, the joint becomes less stable, which can lead to discomfort, altered movement, and changes in the joint over time. Owners often notice a cat favouring one back leg, moving more carefully, or spending less time on higher surfaces. The change in mobility may come on suddenly after a jump or twist, or it may develop more gradually. Some cats show only subtle differences in how they use the leg, particularly in the early stages. This page explores the patterns that may suggest cruciate ligament involvement, the changes that occur within and around the joint, the investigations that help clarify what is happening, and the range of approaches used to manage the condition in cats.
Cruciate Ligament Disease in Dogs
Cruciate ligament disease refers to damage or progressive weakening of one of the major stabilising ligaments inside the stifle (knee) joint. In dogs, this most commonly affects the cranial cruciate ligament, which normally prevents the shin bone from sliding forward relative to the thigh bone during movement and weight-bearing. Owners often first notice a sudden or gradual lameness in a hind leg, sometimes after vigorous activity, sometimes with no clear trigger. The limb may be held up briefly after rest, or the dog may shift weight away from the affected leg when standing. In some dogs, signs develop slowly over weeks or months; in others, a distinct episode of limping marks the beginning. This page explores what cruciate ligament damage looks like from the outside, what happens inside the joint when the ligament fails, how the problem is investigated, and the range of approaches, both surgical and non-surgical, that exist to manage it. Weight, age, activity level, and the degree of instability all shape what may be suitable for an individual dog.
Degenerative Myelopathy in Dogs
A progressive neurological condition affecting the spinal cord, leading to gradual loss of coordination and strength in the hind legs.
Dental Disease in Cats
A progressive condition affecting teeth and oral tissues in cats that often develops silently and alters eating behaviour.
Dental Disease in Dogs
A progressive condition affecting the teeth and gums that can affect eating comfort and quality of life, and has been linked with changes elsewhere in the body.
Discospondylitis
Discospondylitis is an infection involving one or more of the intervertebral discs, the cushioning structures that sit between the bones of the spine, and the adjacent vertebrae themselves. The infection can arrive through the bloodstream from elsewhere in the body, or more rarely through direct penetration or spread from nearby structures. One recognised cause is the bacterium Brucella canis, seen mainly in dogs imported from or with a travel history to countries where it is common, particularly in Eastern Europe. Brucella canis can pass to people and to other dogs, and in England, Scotland and Wales it is reportable to the Animal and Plant Health Agency (APHA). Discospondylitis tends to cause pain localised to the affected area of the spine, and in some cases may affect nerve function if swelling or structural change begins to compress the spinal cord. Owners often notice reluctance to move, stiffness, a hunched posture, or sensitivity when the back is touched. Some dogs show more generalised signs such as reduced appetite or low energy. Fever is present in only a minority of cases, so a normal temperature does not make the condition less likely. New or worsening weakness, wobbling or dragging of the limbs can progress over days and marks a different picture from back pain alone. Cats are less commonly affected, but similar patterns can occur. The signs can develop gradually or appear more suddenly, and the severity varies depending on the location and extent of the infection. This page explores the signals that may appear, what is happening within the spine and surrounding tissues, how the condition is investigated through imaging and laboratory tests, and the range of approaches used to manage infection, pain, and structural stability over time.
Entropion
Entropion describes an inward rolling of the eyelid, so that the edge of the lid and the hairs on its outer surface turn in towards the eye itself. This places fur and skin in direct contact with the cornea (the clear front surface of the eye), which can lead to irritation, discomfort, and damage over time. Owners often notice persistent squinting, watering, or a reluctance to open the affected eye fully, particularly in younger dogs of certain breeds or in older animals, cats in particular, whose eyelid support has changed. The eye may appear red or inflamed, and some pets paw at their face. In many cases, the inward roll is visible when looking at the eye from the side, though subtle cases can be harder to spot. This page explores what entropion looks like in practice, what happens beneath the surface when the eyelid folds inward, how the condition is identified during examination, and the range of approaches (both short-term and longer-term) that exist to address it. The shape and severity vary considerably, and the timeline for intervention depends on the degree of discomfort and risk to the eye.
Glaucoma
Glaucoma describes a group of conditions in which pressure inside the eye becomes elevated, often quite rapidly. The pressure builds when the fluid that normally circulates through the eye cannot drain away properly. Left unchecked, that pressure damages the optic nerve and the light-sensitive structures at the back of the eye, and vision can be lost within hours to days. Owners often notice a red, cloudy, or enlarged eye, sometimes with the dog squinting, holding the eye partly closed, or showing signs of discomfort. The eye may look hazy or bluish, and the pupil may be dilated and unresponsive to light. In many cases the problem starts in one eye, though in primary glaucoma the risk to the fellow eye can be substantial. This page explores the signals that may point towards raised eye pressure, the mechanisms underneath, how the condition is identified and monitored, and the range of approaches used to manage pressure, preserve comfort, and protect remaining vision where possible.
Glaucoma in Dogs
Glaucoma describes a group of conditions in which pressure inside the eye rises above the range the eye can tolerate. That pressure can build quickly or gradually. When it rises suddenly, the retina and optic nerve can be damaged beyond recovery within hours to days, and eyes seen within the first three days of signs are more likely to still have sight than those seen later. When it builds slowly, vision fades over weeks to months. Owners often notice a red, cloudy, or enlarged eye, sometimes with squinting or signs that suggest discomfort. In other cases the eye may look subtly different: slightly wider, or with a pupil that does not respond to light as the other does. Primary glaucoma often starts in one eye, and without preventive drops the second eye followed after a median of about eight months in one study. At home, the red eye of glaucoma can look very like conjunctivitis or uveitis, and eye pressure cannot be judged by looking at or touching the eye; it is measured with a tonometer. This page explores what glaucoma can look like in the early and later stages, what drives the rise in pressure, how it is measured and investigated, and the range of approaches used to manage it. The aim is to help you understand what may be happening and what questions may be worth exploring.
Hip Dysplasia in Dogs
A developmental condition where the hip joint forms abnormally, leading to instability, cartilage wear, and progressive mobility changes.
Hip Luxation
Hip luxation describes what happens when the ball of the femur (thigh bone) slips out of the socket in the pelvis. The joint is no longer sitting in its normal position, and the leg can no longer move in the usual way. This can happen after trauma (a fall, a road traffic accident, or an awkward landing) or occasionally in association with underlying hip disease. Owners often notice sudden, severe lameness in one hind leg. The affected leg may be carried off the ground, appear shorter than the other side, or sit at an unusual angle. Some dogs will still try to bear weight; others will not put the paw down at all. Cats tend to be similarly reluctant to use the leg, and may resist being touched around the hip. This page explores what signs often accompany hip luxation, what is happening at the joint itself, how the condition is confirmed, and the range of approaches, both surgical and non-surgical, that exist to address it. Each approach carries different expectations and tradeoffs, which are discussed in later sections.
Hypertrophic Osteopathy
Hypertrophic osteopathy is a condition in which new bone forms along the outer surface of the limb bones, typically affecting all four legs. This extra bone growth happens in response to something else occurring in the chest or abdomen, most often a mass in the lungs, though other triggers exist. The new bone itself is not the primary problem; it is a reaction. Owners most often notice swelling of the lower legs, which may be firm and warm to the touch, along with stiffness, reluctance to walk, or shifting weight between limbs. The pattern tends to be symmetrical, and the signs can develop gradually or appear over a matter of weeks. The underlying cause may not be obvious from the outside. This page explores what signs may appear, the mechanisms that link distant disease to bone changes in the limbs, how the condition and its cause are investigated, and what approaches exist once the picture becomes clearer.
Intervertebral Disc Disease (IVDD)
Intervertebral disc disease describes a group of conditions in which the cushioning discs between the bones of the spine become damaged, degenerate, or shift out of position. When this happens, the disc material can press on the spinal cord or the nerves that branch from it, interfering with the signals that travel between the brain and the rest of the body. The result can range from discomfort and stiffness to paralysis of the limbs with loss of bladder control. Owners often notice a change in how their dog moves or holds itself: reluctance to jump, a hunched posture, unsteadiness in the back legs, or dragging of the paws. In some cases the change is gradual; in others it appears quite suddenly. Certain breeds, particularly those with long backs or short legs, are seen more frequently, though the condition can occur in any dog. This page explores what may be observed when disc disease is present, the mechanisms that lead to pressure on the spinal cord, how the problem is investigated using imaging and examination, and the range of approaches used to manage it, both supportive and surgical. The course and outcome depend on the severity of nerve involvement, the speed of onset, and the individual animal.
Laryngeal Paralysis
Laryngeal paralysis describes a loss of normal movement in one or both sides of the larynx, the structure at the top of the windpipe that opens during breathing and closes during swallowing. When the cartilages that form the larynx no longer pull apart as they should, the airway narrows, and breathing becomes noisier and more effortful, particularly during exercise or in warm weather. Owners often notice a change in the sound of breathing first: a harsh, raspy noise on the in-breath, sometimes described as roaring or stridor. The change may be gradual, appearing over months, or it may become obvious quite suddenly during exertion or heat, when a dog can tip into a life-threatening breathing crisis. Some dogs also develop a different bark, tire more quickly on walks, or cough or gag when drinking. Laryngeal paralysis is seen most often in older, large-breed dogs, though it can occur in younger animals or smaller breeds in certain contexts. This page explores what laryngeal paralysis may look like in day-to-day life, the mechanisms that can lead to it, how it is investigated, and the range of approaches that exist for supporting affected dogs. The condition varies widely in how it progresses and in the degree to which it affects quality of life, and understanding that spectrum can help frame conversations about monitoring and intervention.
Laryngeal Paralysis in Dogs
A condition where the larynx does not open properly during breathing, causing airway restriction, voice changes, and exercise difficulty.
Legg-Calvé-Perthes Disease
Legg-Calvé-Perthes disease is a condition affecting small breed dogs where the blood supply to the femoral head (the ball of the hip joint) is disrupted, causing bone death and subsequent collapse, leading to pain, lameness, and hip dysfunction.
Lumbosacral Stenosis
Lumbosacral stenosis describes a narrowing of the spinal canal where the lower back meets the pelvis, at the junction between the last lumbar vertebra and the sacrum. This narrowing can put pressure on the nerve roots that emerge at this level, affecting the signals that travel between the spinal cord and the hind limbs, tail, and pelvic organs. It tends to develop gradually and is seen more often in larger breed dogs, particularly German Shepherds, though it can occur in any dog. Owners often notice changes in how their dog moves or behaves during activity: reluctance to jump, difficulty rising after rest, a stiff or altered gait in the hind limbs, or discomfort when the lower back or tail base is touched. Some dogs may lick or chew at the tail or hindquarters, and in some cases there can be changes in tail carriage or, less commonly, bladder or bowel control. This page explores what an owner may observe in a dog with lumbosacral stenosis, what is happening at the affected site, how the condition is investigated through examination and imaging, and the range of approaches (both medical and surgical) that exist to manage pressure on the nerve roots.
Luxating Patella in Dogs
A luxating patella describes a kneecap that moves out of its normal position in the groove at the front of the stifle joint. In many dogs this happens intermittently: the kneecap slips to one side, then returns on its own. In others it may stay displaced for longer periods or become a permanent change in limb structure. Owners often notice a sudden skip or hop on one hind leg during a walk, sometimes described as though the dog is avoiding putting weight down for a few steps before returning to normal. In other cases the pattern may be more persistent lameness, a stiff gait, or a visible difference in how the leg is carried or held. Some dogs show no obvious discomfort at all, and the finding emerges during a routine examination. This page explores the physical signs that can accompany patellar movement, the structural factors that contribute to it, the ways it can be identified and graded during examination, and the range of approaches, both surgical and non-surgical, that exist depending on severity, symptoms, and the individual dog's circumstances.
Medial Shoulder Instability
Medial shoulder instability describes a condition in which the structures that normally hold the shoulder joint stable on its inner (medial) side become lax or damaged, allowing the joint to shift or slide in ways it ordinarily would not. This instability may follow a single injury, such as a fall, a slip or a sudden twist, or develop gradually, often without a known injury. Owners most often notice a front-leg lameness that may appear suddenly or build over time, sometimes shifting in severity or improving with rest before returning. The lameness may be subtle at first and can be mistaken for a paw injury or a more general reluctance to bear weight. This page explores the signs that may point towards medial shoulder instability, the anatomy and mechanics that underpin the condition, the ways in which it is investigated through examination and imaging, and the range of approaches, both conservative and surgical, that exist to support the joint and manage discomfort.
Osteoarthritis in Dogs
A progressive joint condition involving cartilage breakdown, inflammation, and pain that affects mobility and comfort over time.
Osteochondritis Dissecans (OCD)
Osteochondritis dissecans is a developmental condition affecting joint cartilage in growing dogs, where abnormal cartilage formation can lead to loose fragments within joints, causing pain and lameness, most commonly affecting the shoulder, elbow, stifle, or hock.
Osteomyelitis
Osteomyelitis is an infection within the bone itself. It develops when bacteria reach the bone tissue, most often through a deep or penetrating wound such as a bite, after trauma such as a road traffic accident, or following surgery, and only rarely through the bloodstream from an infection elsewhere in the body. The infection triggers inflammation inside the bone, which can interfere with healing and, over time, with the bone's structure. Owners often notice persistent pain in a limb, reluctance to bear weight, or swelling that does not resolve as expected after an injury or procedure. In some cases, there may be a wound that continues to drain or fails to heal. The signs can develop over days to weeks, and the affected area may feel warm or appear tender when touched. This page explores the patterns that can raise concern for osteomyelitis, what is happening within the bone and surrounding tissue, how the condition is investigated through imaging and laboratory work, and the range of approaches that may be considered in managing it.
Panosteitis
Panosteitis is a condition affecting the long bones of growing dogs, in which inflammation develops within the bone marrow cavity itself. It tends to appear during periods of rapid growth, most often between five and eighteen months of age, and can shift from one leg to another over weeks or months. Owners often notice sudden-onset limping that may seem to move around: a dog who was favouring the right foreleg last week may now be uncomfortable in the left hind. The lameness can be mild or quite pronounced, and many dogs show signs of discomfort when the affected bone is pressed. The pattern can be puzzling because it tends to come and go, and because multiple legs may be involved at different times. This page explores what panosteitis can look like when it first appears, what is thought to be happening inside the bone, how the condition is typically investigated, and the range of approaches that exist for managing discomfort while the inflammation resolves.
Patellar Luxation
Patellar luxation describes a kneecap that moves out of its normal position in the groove at the front of the thigh bone. In dogs, this can happen as a brief slip that resolves on its own, or as a more persistent displacement. The underlying cause may be developmental (related to the shape and alignment of the leg bones as the dog grows) or may follow injury. Owners often notice a sudden hop or skip in one back leg during a walk, sometimes followed by the leg returning to normal a few strides later. In other cases, a pet may carry one leg for longer periods, or move with a persistently altered gait. The pattern can be intermittent or constant, mild or more limiting, and may involve one leg or both. This page explores what those patterns can signal, the structural factors that allow the kneecap to move, how the condition is examined and graded, and the range of approaches (from monitoring and supportive care to surgical correction) that exist depending on severity, comfort, and the functional impact on the individual animal.
Sacroiliac Disease in Dogs
Sacroiliac disease refers to discomfort or dysfunction arising from the sacroiliac joints, the paired joints that connect the spine to the pelvis on each side of a dog's hindquarters. These joints allow a small degree of movement and bear considerable load during walking, running, and turning. When they become strained, inflamed, or unstable, the result can be pain that affects how a dog moves and carries weight through the back legs. Owners often notice changes in gait: stiffness when rising, reluctance to jump or climb stairs, a shortened stride, or subtle asymmetry in the hindquarters. Some dogs shift weight away from one side, or show discomfort when the lower back or pelvis is touched. Because the signs can overlap with hip problems, lumbar spine conditions, or generalised muscle soreness, sacroiliac disease is not always the first consideration. This page explores the signals that may point towards sacroiliac involvement, the mechanical and inflammatory processes that can occur at these joints, the ways the condition can be investigated, and the range of approaches (from rest and physiotherapy to targeted treatments) that can be considered depending on the individual dog and the nature of the problem.
Spondylosis in Dogs
Spondylosis is the formation of small bony bridges that grow between adjacent vertebrae in the spine, typically along the underside of the spinal column. These bridges develop as a response to wear and movement over time, most often in older dogs, and represent the skeleton's way of reinforcing segments that have become less stable as the soft tissues between the bones age. Many dogs with spondylosis show no signs at all, and the changes are discovered incidentally on X-rays taken for other reasons. When signs do appear, they tend to be subtle: a slightly altered gait, occasional stiffness after rest, reluctance to jump or climb stairs, or sensitivity when the back is touched. The pattern and severity vary widely, depending on where the bridges form and whether a spur presses on a nerve root where it leaves the spine. This page explores what can be observed in a dog with spondylosis, what is happening beneath the surface in the spine, how the condition is identified through imaging, and the range of approaches used when discomfort or limitation is present.
Supraspinatus Tendinopathy
Supraspinatus tendinopathy describes a problem with the supraspinatus tendon, which connects a shoulder muscle to the top of the upper arm bone in the front leg. The tendon can become damaged, inflamed, or begin to break down over time, often in response to repeated strain or wear. This is one of the more common soft-tissue problems affecting the shoulder in dogs, and it is rare in cats. Owners often notice a front-leg lameness that may come and go, or a reluctance to bear full weight after exercise or rest. The limb may appear stiff when the dog first gets up, or the dog may hold the leg in a slightly altered position. Some dogs show discomfort when the shoulder is moved in particular ways, or when pressure is applied over the front of the shoulder. This page explores the signs that may point towards supraspinatus tendinopathy, what is happening within the tendon and surrounding structures, how the condition is investigated through examination and imaging, and the range of approaches that exist to support healing and manage discomfort. The course can vary widely depending on the severity of tendon damage and the individual animal's activity level and build.
Syringomyelia
Syringomyelia is a condition in which fluid-filled cavities form within the spinal cord. These cavities, called syrinxes, develop when the normal flow of cerebrospinal fluid around the brain and spinal cord is disrupted, often because the space at the back of the skull is smaller than typical. The condition is seen most often in certain toy breeds, particularly Cavalier King Charles Spaniels, though it can occur in other dogs and occasionally in cats. Owners may notice signs that suggest discomfort around the head, neck, or shoulders: scratching at the air near the ear without making contact with the skin, sensitivity when the neck or collar area is touched, reluctance to jump or play, or vocalisation during certain movements. Some animals show no outward signs at all, while others develop changes in gait or coordination over time. The signs can be subtle at first and may be mistaken for skin irritation, ear trouble, or general stiffness. This page explores what signals may be observed, what is happening inside the skull and spine, how the condition is investigated using imaging, and what approaches exist to manage discomfort and slow progression. The course varies widely between individuals, and decisions about investigation and management depend on the severity of signs, the animal's age and general health, and what is practical in each household.
Syringomyelia (CM/SM)
Syringomyelia describes the development of fluid-filled cavities within the spinal cord itself. These cavities form when the normal flow of cerebrospinal fluid around the brain and spinal cord is disrupted, often because the space at the back of the skull is smaller than usual. The condition is seen most often in certain breeds, particularly Cavalier King Charles Spaniels, though it can occur in others. Owners may notice signs that suggest discomfort in the head or neck, such as scratching at the air near the ear or shoulder without making contact with the skin, reluctance to be touched around the head, sensitivity to collar pressure, or changes in behaviour during excitement or rest. Some dogs show no outward signs at all, while others may develop difficulty walking or coordinating movement if the cavities affect larger portions of the spinal cord. The picture varies widely between individuals. This page explores what these signs may reflect, how the condition is identified through imaging, the factors that influence whether and how it progresses, and the range of approaches (both medical and surgical) that exist to manage it. The goal is to help you understand what syringomyelia can look like and what the options are, not to tell you what is happening in your own dog.
Tarsal Hyperextension Injury
Tarsal hyperextension injury describes a situation in which the hock (the angular joint roughly midway down the hind leg) drops lower than usual when weight is placed on the limb, sometimes touching or nearly touching the ground. This happens when the structures that normally hold the joint in its natural position (ligaments, tendons, the joint capsule itself) are stretched, torn, or otherwise compromised. The change in posture is often visible when the dog or cat walks or stands, and the limb may appear to sink or flatten at the hock. Owners often notice a sudden or progressive change in the way the hind leg looks when their pet moves, perhaps after a fall, a jump, or sometimes without an obvious incident. The limb may still bear weight, but the hock sits closer to the ground than the opposite side, and the gait may look awkward or effortful. In some cases the change is subtle; in others the joint appears to collapse entirely when standing. This page explores what signals tend to accompany this kind of injury, what is happening to the structures inside and around the hock, how the injury is investigated, and what approaches exist for managing it. The shape and severity of the problem can vary considerably, and the path forward depends on the extent of the damage and the individual animal's circumstances.
Tooth Resorption
Tooth resorption involves progressive destruction of tooth structure, commonly affecting cats over five years of age and often causing significant oral discomfort.
Tracheal Collapse
Tracheal collapse describes a progressive weakening of the cartilage rings that normally hold the windpipe open. As these rings lose their rigidity, the trachea can flatten during breathing, partially obstructing the flow of air. The change tends to develop gradually, though the signs may appear suddenly or worsen under certain conditions. Many owners first notice a dry, honking cough that sounds distinct from other respiratory noises, often described as similar to a goose call. The cough may appear during excitement, exercise, or when pressure is applied to the neck, such as from a collar. Some dogs may also show rapid breathing, noisy inhalation, or reluctance to exercise, particularly in warm weather or during stress. This page explores the signs that may accompany tracheal collapse, the structural and functional changes occurring in the airway, the diagnostic approaches used to assess the trachea, and the range of medical and procedural options that exist to manage airflow and quality of life.
Wobbler Syndrome (Cervical Spondylomyelopathy)
Wobbler syndrome describes a group of conditions affecting the neck vertebrae and spinal cord in dogs, most often seen in large and giant breeds. The bones, discs, or ligaments in the cervical spine can compress the spinal cord, interfering with the signals that coordinate movement. Signs usually develop gradually but can also start or worsen suddenly, and they can range from subtle changes in gait to more pronounced difficulty walking. Owners often notice an unsteady, wobbly quality to the hind limbs first: a swaying or crossing of the back legs, or a sense that the dog is not quite sure where its feet are. The front limbs may show a stiff or shortened stride. Some dogs appear uncomfortable in the neck, reluctant to lower the head, or slow to rise. The pattern and severity vary, and the progression can be slow or more rapid depending on the underlying cause. This page explores the signals that may suggest spinal cord compression in the neck, the anatomical changes that can produce those signals, the imaging and other investigations used to characterise the problem, and the medical and surgical approaches that exist. The goal is to help you understand what may be happening and what the shape of the conversation with your veterinary team might look like.
Cognitive & Behavioural Health
Acral Lick Dermatitis
Acral lick dermatitis, also known as lick granuloma, develops when dogs persistently lick a specific area, usually on a lower leg, creating a thickened, often ulcerated lesion, with the behaviour typically reflecting an interplay of physical discomfort, psychological factors, and self-perpetuating habit.
Aggression in Dogs
Aggression in dogs describes behaviour directed at causing another individual (human, dog, or other animal) to move away or stop what they are doing. It exists on a spectrum, from a subtle freeze or hard stare through to growling, snapping, or biting. What an owner observes can vary widely depending on context, the dog's learning history, and what has worked for that dog in the past. Many owners arrive at this page after a specific incident: a snap at a visitor, a fight with another dog, guarding of food or space, or reactivity on the lead. Others are noticing patterns: tension around certain triggers, changes in how their dog responds to handling, or escalation over time. Aggression is not a diagnosis in itself; it is a category of behaviour that can arise from fear, frustration, pain, learned responses, or difficulty processing the environment. This page explores the signals that often precede or accompany aggressive behaviour, the range of factors that can contribute, how the behaviour is assessed, and the environmental, medical, and behavioural approaches that may be considered. The aim is to help you understand what you are observing and the shape of the conversation that may follow.
Attention-Seeking Behaviour
Attention-seeking behaviour describes patterns where a dog or cat has learnt that certain actions, such as barking, pawing, jumping, vocalising, or other persistent behaviours, reliably produce a response from the people around them. The behaviour itself may be normal in origin, but it becomes reinforced when it consistently results in attention, even if that attention is verbal correction or physical redirection. Over time, the animal may increase the frequency or intensity of these behaviours, particularly if other, quieter methods of communication have been less effective. Owners often notice repeated actions that seem designed to provoke interaction: a dog that barks until spoken to, a cat that knocks objects off surfaces while making eye contact, or persistent pawing during moments of rest. These patterns can develop in otherwise healthy animals and may intensify during periods of change, boredom, or when the animal's routine needs are inconsistent. The behaviour is not typically a sign of spite or manipulation in the human sense, but rather a learnt strategy that has worked in the past. This page explores what attention-seeking behaviour can look like in practice, the learning processes and environmental factors that tend to sustain it, how the pattern is identified and distinguished from other causes of persistent behaviour, and the range of approaches that can alter the cycle, including changes to routine, environment, and the way responses are given.
Border Collie Collapse
Border Collie Collapse describes episodes in which a Border Collie becomes suddenly unsteady, disoriented, or unable to continue during or shortly after strenuous exercise, most often repeated ball retrieving or herding, and sometimes agility or flyball. The dog may stagger, sway, fall to the side, or appear dazed, and in the published descriptions gait and awareness return to normal within 30 minutes of rest. Signs can appear after 5 to 15 minutes of strenuous activity, particularly in warm weather. The same or a very similar pattern is described in related breeds, including Australian Shepherds, Kelpies, Bearded Collies, Shetland Sheepdogs and Whippets. Owners often arrive at this page wondering whether what they witnessed was a seizure, heatstroke, or heart problem, particularly if it was the first time it happened. The dog may have seemed fine beforehand and returns to normal behaviour afterwards, which can make the episode difficult to interpret. Watching the dog does not settle that question: heatstroke and heart disease can look the same at the moment of collapse, and Border Collie Collapse is diagnosed only once other causes have been excluded. This page explores the signals that may point towards Border Collie Collapse, what is understood about the mechanism underneath, how the condition is investigated and distinguished from other causes of exercise-related collapse, and the approaches that exist for managing affected dogs.
Caffeine Toxicity
Caffeine toxicity occurs when a dog or cat consumes enough caffeine to overstimulate the nervous system and heart. Sources may include coffee (brewed or grounds), tea, energy drinks, caffeine tablets, or certain foods and medications containing caffeine. Dogs and cats are more sensitive to caffeine's effects than humans; in dogs, caffeine is cleared at a broadly similar rate to humans, though comparable clearance data are not established in cats. Clinical signs can develop within one to two hours of ingestion. Owners often arrive on this page after their pet has accessed coffee, an energy drink, or caffeine-containing products, and may notice restlessness, panting, vomiting, a rapid heart rate, tremors, or agitation. The severity depends on the amount consumed and the size of the animal. In some cases, caffeine is ingested alongside chocolate, which contains both caffeine and theobromine (a related compound with a longer half-life in dogs). This page explores the signs that can appear after caffeine ingestion, the mechanisms by which caffeine affects the body, how veterinary professionals assess the exposure and clinical state, and the approaches used to manage toxicity. There is no specific antidote; supportive measures aim to limit absorption, support organ function, and manage symptoms until caffeine is cleared from the body.
Canine Cognitive Dysfunction
An age-related condition affecting brain function in older dogs, leading to changes in memory, awareness, and learned behaviours.
Compulsive Behaviour in Dogs
A behavioural condition involving repetitive actions performed out of context that may reflect underlying stress, frustration, or neurological factors.
Epilepsy in Cats
Epilepsy describes a pattern of recurring seizures that arise from abnormal electrical activity in the brain. A seizure may appear as a sudden collapse with paddling limbs and loss of awareness, or as something more subtle: repeated twitching, staring into space, or unusual repetitive movements. Between episodes, many cats appear entirely normal. Owners often arrive at this page having witnessed a frightening event, or after noticing episodes that seem to come and go without obvious cause. Epilepsy in cats is less common than in dogs, and the underlying reasons vary. In some cases no cause is found, while in others the seizures arise from disease within the brain. Seizures caused by illness elsewhere in the body, or by a toxin, can look the same but are not classed as epilepsy. This page explores what seizures can look like, what may be happening beneath the surface, how the pattern is investigated, and the approaches that exist to reduce their frequency and severity. The aim is to help you understand the territory, not to diagnose what your own cat is experiencing.
Epilepsy in Dogs
Epilepsy describes a pattern of recurring seizures: moments when electrical activity in the brain becomes suddenly disordered, producing visible changes in movement, awareness, or behaviour. In many dogs, no underlying cause can be identified through testing; in others, seizures arise from structural brain changes, metabolic disturbances, or exposure to certain substances (the last two are reactive seizures rather than epilepsy). Owners most often arrive on this page after witnessing a first seizure or after a pattern has emerged. What was observed may range from brief, subtle episodes (a vacant stare, rhythmic facial twitching) to full-body convulsions lasting one or two minutes. A seizure that continues beyond five minutes is a different and life-threatening event, described under the later signs. The experience tends to be distressing to witness, and questions commonly centre on what caused the event, whether it will recur, and what can be done. This page explores the observable signs that accompany seizure activity, the investigative steps used to understand what may be driving the pattern, and the medical approaches that exist to reduce seizure frequency or severity over time. The course and outlook vary widely between individuals.
Episodic Falling Syndrome
Episodic falling syndrome is an inherited condition seen almost exclusively in Cavalier King Charles Spaniels, in which episodes of muscle stiffness prevent normal movement during moments of excitement, play, or exertion. An affected dog may suddenly freeze mid-stride, fall onto their side with rigid limbs, or adopt a bunny-hopping gait, all while remaining conscious and aware. The episodes typically last seconds to minutes, then resolve completely. Owners often arrive on this page because they have witnessed a collapse or stumble that looked alarming but did not follow the pattern of a seizure: the dog's eyes stayed open, they seemed awake, and they recovered quickly once the excitement passed. The episodes tend to begin in young dogs and can vary in frequency and severity over time. This page explores what these episodes may look like in practice, the underlying genetic and neurological mechanisms, how the condition is investigated and distinguished from other causes of collapse, and the medical and management approaches that can reduce episode frequency and severity.
Excessive Vocalisation in Cats
Excessive vocalisation describes a pattern where a cat meows, yowls, or cries more frequently, more loudly, or at unusual times, often enough that an owner notices a change from what is typical for that individual. Cats vocalise for many reasons, and what feels excessive depends partly on the cat's baseline: some breeds and individuals are naturally more talkative, while others rarely make a sound. Owners often arrive here because their cat has started calling out at night, meowing persistently near food or litter, yowling without obvious cause, or vocalising in ways that feel different from ordinary communication. The sound itself can vary from quiet, repetitive meows to loud, distressed-sounding cries, and the context in which it happens (time of day, location, and whether the cat seems settled or unsettled) often shapes what the owner is wondering about. This page explores the signals that can accompany changes in vocalisation, the range of things that may be happening underneath (from medical causes such as pain, sensory change, or cognitive shifts, to behavioural and environmental factors), how the pattern is investigated, and the approaches that exist depending on what is found.
Exercise-Induced Collapse
Exercise-induced collapse is an inherited disorder that causes otherwise healthy dogs to lose control of their hind limbs during or shortly after intense activity. It is seen mainly in Labrador Retrievers and is caused by an autosomal-recessive mutation in the DNM1 gene. The same mutation has been found in several other breeds: Chesapeake Bay Retrievers, Curly-Coated Retrievers, Boykin Spaniels, Cocker Spaniels, German Wirehaired Pointers, Old English Sheepdogs, Bouviers des Flandres and Pembroke Welsh Corgis. Affected dogs typically appear normal at rest and during light to moderate exercise, but within 5 to 20 minutes of vigorous running, retrieving, or play, they may develop a characteristic wobbling gait, stumbling, or collapse that begins in the hind legs and can progress forward. Owners often describe a dog who was playing enthusiastically one moment and suddenly unable to coordinate their back end the next, though the dog remains conscious throughout. Most episodes resolve with rest, although a few dogs have died during or just after one. Many dogs seem keen to continue playing even as the signs appear. The pattern can be confusing because the same dog may exercise without incident on other occasions, particularly if the activity is less intense or the weather is cooler. This page explores what these episodes can look like in detail, the genetic and physiological basis for the condition, how it is distinguished from other causes of exercise intolerance or weakness, and the role of DNA testing in identifying affected and carrier dogs. It also considers the approaches available for managing affected animals and the implications for breeding decisions.
Facial Nerve Paralysis
Facial nerve paralysis describes a loss of normal movement on one side of the face, caused by disruption to the nerve that controls the muscles of facial expression. The facial nerve also carries fibres responsible for tear production and some aspects of taste, so changes in these functions can occur alongside the visible asymmetry. Owners often notice that one side of the face appears drooped or slack, that the ear on the affected side hangs lower, or that the eye on that side does not blink normally. Drooling from one side of the mouth, difficulty holding food, or a change in the shape of the muzzle when the dog or cat is at rest may also prompt concern. In some cases the onset follows an ear infection or head trauma, but in many animals no clear trigger is identified. This page explores the patterns that suggest facial nerve involvement, the mechanisms that can disrupt the nerve's function, the investigations used to clarify the picture, and the range of approaches taken when managing the condition and its effects.
Fear Aggression in Dogs
Fear aggression describes behaviour in which a dog uses aggression (growling, snapping, lunging, or biting) as a defensive response to something it perceives as threatening. The threat may be a person, another animal, an object, a sound, or a situation the dog has learned to associate with danger or discomfort. The behaviour often emerges when the dog feels cornered, unable to escape, or when earlier, subtler signals of fear have been ignored. Owners often notice this pattern in specific contexts: a dog that barks and lunges when approached by strangers, snaps when handled near the face or paws, or becomes defensive when confined or startled. The dog may show other signs of fear beforehand (ears back, tail tucked, body lowered and whites of the eyes visible), though in some cases the aggression appears suddenly, particularly if the dog has learned that earlier warning signals are ineffective. This page explores what fear aggression looks like in practice, the physiology and learning processes that underlie it, how the behaviour is investigated and distinguished from other forms of aggression, and the range of management and modification approaches used in dogs living with this response.
Feline Cognitive Dysfunction
Feline cognitive dysfunction describes a progressive decline in brain function that can occur as cats age, affecting memory, awareness, learned behaviours, and social interaction. It shares features with dementia in humans, though the pace and pattern can vary considerably between individuals. Owners often notice changes such as altered sleep patterns, wandering or appearing lost in familiar spaces, changes in greeting behaviour or social responsiveness, increased vocalisation (particularly at night), and house-soiling that appears unrelated to other medical causes. These signs tend to emerge gradually, and may initially be subtle or attributed to "just getting older". This page explores the signals that can appear, what is understood about the underlying changes in the ageing feline brain, how cognitive decline is distinguished from other conditions, and the range of approaches (environmental, behavioural, nutritional and pharmacological) that may influence progression or quality of life.
Flank-Sucking in Dobermanns
Flank-sucking is a repetitive behaviour seen almost exclusively in Dobermanns, in which the dog repeatedly grasps a fold of skin along its own flank or lower chest in its mouth and sucks or chews at it, often for sustained periods. The behaviour can occur daily, sometimes for an hour or more, and may appear focused, trance-like, or difficult to interrupt. The coat in the area may become wet, stained, or thinned over time, and in some dogs the sucking is intense enough to cause physical problems that need veterinary treatment. Owners often notice it during periods of inactivity or just before sleep, and may wonder whether the dog is trying to soothe itself, whether it is a learned habit, or whether something medical is being missed. The behaviour tends to be persistent once established, and its meaning and management are not always straightforward. This page explores the signs that distinguish flank-sucking from other repetitive or oral behaviours, what is understood about why it happens in this breed, how it is investigated, and the range of approaches (environmental, behavioural, and medical) that may be considered.
Generalised Anxiety in Dogs
Generalised anxiety in dogs describes a pattern in which a dog appears persistently uneasy, vigilant, or on edge across many different contexts, rather than in response to a specific trigger or situation. This differs from fear of particular things: a dog with generalised anxiety may seem unable to settle even when the environment appears calm and familiar. Owners often notice restlessness, difficulty relaxing at home, hypervigilance to sounds or movement, or a dog that seems to expect something worrying at any moment. Some dogs may follow their owner constantly, startle easily, or show physical signs such as panting, pacing, or tension in the body. The pattern tends to be ongoing rather than linked to a single event or change. This page explores what generalised anxiety can look like in daily life, what may be happening in the brain and body to sustain that state, how the pattern is recognised and distinguished from other possibilities, and the range of approaches (environmental, behavioural and pharmacological) that exist to support dogs living with persistent anxiety.
Granulomatous Meningoencephalomyelitis (GME)
Granulomatous meningoencephalomyelitis is an inflammatory condition affecting the brain, spinal cord, or both. The inflammation develops when clusters of immune cells form in or around the protective layers and tissue of the central nervous system, though why this happens in individual animals remains incompletely understood. Owners often notice changes that can appear quite suddenly: altered behaviour, difficulty with coordination or balance, seizures, weakness in one or more limbs, changes in vision, or a head tilt. The pattern varies depending on which part of the nervous system is affected, and signs may progress over days to weeks. Because the signs can overlap with other neurological conditions, the path to understanding what is happening typically involves detailed examination and imaging. This page explores the signals that may prompt investigation, what is understood about the underlying process, how the condition is identified through clinical assessment and testing, and the range of approaches used to manage inflammation and support quality of life.
Hydrocephalus
Hydrocephalus describes an abnormal accumulation of cerebrospinal fluid within the brain's ventricular system. The fluid, which normally cushions and nourishes the brain, builds up when production exceeds absorption, or when the normal circulation pathways become obstructed. This can lead to increased pressure inside the skull and, in young animals with open skull sutures, an enlarged, dome-shaped head. Owners most often notice hydrocephalus in puppies or kittens, where a disproportionately large head may be accompanied by behavioural changes, difficulty learning, altered gait, or seizures. In some cases the condition is identified incidentally on imaging performed for other reasons, and the animal may show few or no outward signs. Certain toy and brachycephalic breeds are seen more frequently, though hydrocephalus can occur in any dog or cat. This page explores the signs that may be observed, the mechanisms and causes underlying fluid accumulation, how hydrocephalus is investigated through imaging and clinical examination, and the medical and surgical approaches that exist to manage it.
Idiopathic Generalised Tremor Syndrome
Idiopathic generalised tremor syndrome describes a pattern in which a dog develops rhythmic shaking or trembling that affects much of the body, without an identified underlying cause. The tremors tend to be most visible when the dog is awake and standing, and often lessen or disappear during sleep or rest. The condition most commonly appears in young adult dogs, and small white-coated breeds have historically been reported more frequently, though it can occur in dogs of any size or colour. Owners typically notice a fine or coarse shaking that may involve the head, body, and limbs. The dog remains conscious and alert, and the tremors themselves do not usually cause pain, though they can make movement less coordinated. The onset may be gradual or sudden, and in many cases the tremors fluctuate in severity over hours or days. Sudden whole-body tremor cannot be told apart from poisoning at home. In a UK referral series of 198 dogs with generalised tremor, poisoning was the most common cause (46%). Where the poison was identified, it was most often tremorgenic mycotoxins from mouldy food or compost, or metaldehyde slug bait. This syndrome accounted for about a quarter. Metaldehyde signs begin 30 minutes to 6 hours after eating it and can progress to seizures and a body temperature above 41°C, and deaths usually occur within 4 to 24 hours. This page explores the signals that may accompany this pattern of tremor, what is understood about the processes that may be involved, the investigations that help distinguish it from other causes of shaking, and the approaches that exist to manage the tremors when they affect a dog's comfort or function.
Idiopathic Head Tremors
Idiopathic head tremors are episodes of rhythmic, involuntary shaking of the head that occur in dogs, typically without any identifiable underlying cause. The movement can be horizontal (like a 'no' gesture), vertical (like a 'yes' nod), or occasionally rotational. Episodes tend to be brief, often lasting a few seconds to several minutes and occasionally longer, and the dog usually remains conscious and aware during the event. Owners often describe sudden-onset head bobbing or trembling that appears out of nowhere and then resolves on its own. The episodes can look unsettling, and many owners arrive wondering whether their dog has had a seizure or whether something more serious is happening in the brain. The tremors themselves do not appear to cause pain, and most dogs can be distracted or have the episode interrupted, which is not typical of a generalised seizure, although the same is seen when a head tremor has a structural cause. This page explores the patterns that may signal idiopathic head tremors, what is understood (and not yet understood) about the mechanisms involved, how the condition is investigated to distinguish it from other neurological events, and the range of approaches that exist for managing episodes when they occur.
Inappropriate Elimination in Cats
Inappropriate elimination describes situations where a cat urinates or defecates outside the litter tray, in places the household does not expect. This can range from occasional accidents to a persistent pattern, and may involve urine alone, faeces alone, or both. The underlying causes span a wide spectrum: medical conditions affecting the bladder, bowel, or mobility; stress or anxiety changing how a cat perceives its environment; learned aversions to the tray itself; age-related changes in cognition; and loss of continence. Owners often arrive at this question after finding urine on soft furnishings, discovering faeces in corners or bathtubs, or noticing their cat straining near the tray but not inside it. The behaviour can appear suddenly or develop gradually, and the location, posture, and frequency all offer clues to what may be driving it. Distinguishing between a cat that cannot reach the tray in time, one that finds the tray aversive, and one that is marking territory requires careful observation. This page explores the signals that help narrow the picture, the mechanisms (medical and behavioural) that can produce these patterns, the investigations that may be relevant, and the range of approaches used to address the underlying contributors.
Inter-Cat Aggression
Inter-cat aggression describes hostile or threatening behaviour between cats living in the same household. It can range from subtle posturing (a stare, a blocked doorway or a tense body) to overt physical conflict. The pattern may emerge suddenly after years of peaceful coexistence, or it may have been present, quietly, from the beginning. Owners often arrive at this page because they have seen hissing, swatting, chasing, or outright fighting. In some cases, one cat may avoid certain rooms, eat less, or seem persistently anxious, while the other appears calm. The signs can be episodic or persistent, and the triggers are not always obvious. This page explores the signals that suggest inter-cat tension, the social and physiological factors that can drive it, how the situation is typically assessed, and the range of approaches (environmental, behavioural, and medical) that may help reduce conflict and improve quality of life for both animals.
Maternal Aggression in Dogs
Maternal aggression describes protective behaviour shown by a nursing dam towards people or other animals who approach her puppies. The dam may stiffen, growl, bare her teeth, or snap when someone reaches towards the litter, enters the whelping area, or handles a pup. This behaviour may be unexpected in a dog who was previously calm and social. Owners often arrive on this page because a family dog has become defensive after whelping, or because they are unsure whether the dam's guarding is a normal part of motherhood or a sign that something is wrong. The behaviour is often most pronounced early in lactation, gradually easing as puppies mature and hormonal influence wanes. This page explores what prompts the protective response, how it presents across different contexts and individuals, how it is distinguished from other forms of aggression or distress, and what approaches exist to reduce risk and support a safe environment during lactation.
Necrotising Meningoencephalitis (NME)
Necrotising meningoencephalitis is an inflammatory condition affecting the brain in which areas of tissue become damaged and die, primarily in certain small dog breeds. The inflammation targets both the membranes surrounding the brain and the brain tissue itself, in some breeds affecting the outer layers and deeper tissue of the cerebrum together, while in others the damage concentrates in different regions such as the brainstem or the connecting white matter pathways. Owners often arrive on this page because their dog has developed seizures, changes in behaviour, or difficulty with coordination or vision, typically over days to weeks. These signs can vary widely depending on which part of the brain is affected, and the same outward change may have many possible causes. This page explores what these signs may point to, what is understood about the underlying process, how the condition is investigated through imaging and other tests, and what approaches are used to manage inflammation and support quality of life.
Noise Phobia in Dogs
A behavioural condition involving intense fear responses to sounds such as thunder, fireworks, or other loud noises.
Noise Phobias
Noise phobias involve intense fear responses to sounds such as fireworks, thunder, or household noises, often causing significant distress and behavioural changes in affected dogs.
Pain-Related Aggression in Dogs
Pain-related aggression describes defensive behaviour that arises when a dog is experiencing discomfort or anticipates that something will hurt. The dog may growl, snap, or bite in situations that would not typically provoke a reaction, often when being touched, moved, or approached in particular ways. This is not a temperament problem; it is a protective response to a physical sensation. Owners often notice a sudden change: a normally tolerant dog becomes reactive during grooming, refuses to be lifted, or guards a particular part of the body. The behaviour may appear unpredictable if the underlying discomfort is not yet obvious. In some cases, the pain itself is intermittent or subtle, and the aggression becomes the first clear signal that something is wrong. This page explores what pain-related aggression can look like in practice, the types of discomfort that may drive it, how the underlying cause is identified, and the approaches used to address both the behaviour and the pain beneath it.
Phobia of Vehicles in Dogs
A phobia of vehicles in dogs describes an intense, persistent fear response to cars, vans, lorries, or other motor vehicles. The fear may be triggered by the sight, sound, or proximity of vehicles, or by the prospect of travelling inside one. This is distinct from general nervousness or mild reluctance: phobic responses tend to be marked, disproportionate, and difficult for the dog to recover from without intervention. Owners often notice signs such as trembling, panting, drooling, or attempts to escape when a vehicle approaches or when the dog is asked to get into a car. Some dogs may freeze, refuse to walk near roads, or show distress well before a journey begins. The fear can develop after a specific incident, emerge gradually during early life, or appear without an obvious trigger. It may affect daily routines, limit travel, and create stress for both dog and household. This page explores the signals that may indicate a vehicle phobia, what may be happening in the dog's emotional and physiological experience, how the problem is typically assessed, and the range of approaches (behavioural, environmental, and occasionally pharmaceutical) that can be considered. The goal is to help you understand the nature of the response and the tools available to address it.
Pica in Dogs
Pica describes the repeated eating of things that are not food: soil, stones, fabric, wood, plastic, or other objects that offer no nutritional value. It is not the same as a puppy mouthing everything during exploration, or an adult dog swallowing something unusual once. Pica is a pattern: the behaviour happens again and again, often with a particular type of material, and it can lead to blockages, tooth damage, or poisoning depending on what is consumed. Owners often notice shredded fabric, missing socks, soil disturbed in the garden, or stones that reappear in vomit or stool. Sometimes the eating is witnessed; sometimes it is inferred from what goes missing or what is found later. The behaviour may be calm and focused, or it may happen during stress, boredom, or frustration. In some cases, there is an underlying medical cause (a nutritional deficiency, digestive discomfort, or a neurological change), and in others, the driver is primarily behavioural. This page explores what pica can look like in practice, the medical and behavioural mechanisms that may contribute, how the pattern is investigated, and the range of approaches that may be considered depending on what is found.
Predatory Behaviour in Dogs
Predatory behaviour in dogs refers to sequences of action that resemble hunting (stalking, chasing, grabbing and shaking) directed at moving objects, animals, or sometimes people. These behaviours are normal parts of canine biology, shaped by ancestry and breed history. Directed at livestock, small pets or people, they become a serious risk: predatory attacks usually come with no warning and are likely to cause substantial injury, and babies, young children and small animals are at particular risk because their size and movement resemble prey. Owners often notice a sudden shift in focus when their dog spots something moving: the body may lower, the gaze fixes, and the dog may begin to stalk or chase with little response to calling. In some cases, the behaviour ends with play or curiosity; in others, it escalates to grabbing or shaking. The question is usually not whether the behaviour is present, but what triggers it, whether it is directed at animals or people, and whether the dog can be interrupted or redirected. This page explores the signals that suggest predatory sequences are active, what drives these behaviours at a biological and learned level, how the pattern is assessed, and what approaches exist to manage safety and reduce conflict. It does not cover aggression rooted in fear, frustration, or social conflict, which follow different pathways.
Pseudopregnancy (False Pregnancy)
Pseudopregnancy, or false pregnancy, occurs when hormonal changes in unspayed female dogs trigger physical and behavioural signs mimicking pregnancy and nursing in a bitch that is not pregnant, whether or not she was mated.
Resource Guarding in Dogs
Resource guarding describes behaviour in which a dog defends access to something they perceive as valuable, such as food, toys, spaces, or even people. The guarding can range from subtle stiffening or a fixed stare through to growling, snapping, or biting when someone approaches. It often emerges around food bowls or high-value items, though it can extend to furniture, doorways, or locations the dog has claimed. Owners typically notice this when a dog who seems friendly in other contexts becomes tense, visibly worried, or overtly defensive when a particular resource is present or anticipated. The behaviour may appear suddenly or build gradually, and it can be directed at people, other dogs, or both. Many owners arrive wondering whether what they are seeing is normal possessiveness, whether it will escalate, and what might be driving it. This page explores the signals that may indicate resource guarding, the emotional and learning processes that tend to underlie it, how the behaviour is assessed, and the range of approaches used to address it. The goal is to help you understand what may be happening and what shape intervention typically takes.
Separation Anxiety in Dogs
A behavioural condition where dogs experience distress when separated from their owners, expressed through vocalisation, destruction, or elimination.
Storm Phobia in Dogs
Storm phobia in dogs describes a pattern of fear responses that occur when a dog detects cues associated with thunderstorms: sounds, changes in atmospheric pressure, visual flashes and, some have proposed, static electricity. The response tends to go beyond mild unease and can include trembling, pacing, hiding, drooling, destructive behaviour, or attempts to escape. Some dogs react to distant rumbles or darkening skies before a storm arrives, whilst others respond only when thunder is overhead. Owners often arrive at this page because their dog has begun reacting intensely during storms, the behaviour has worsened over time, or they are wondering whether what they observe is normal wariness or something that may benefit from attention. The reaction may be confined to storms or may extend to other loud or unpredictable events. This page explores the signs that suggest storm phobia, what is understood about why it develops and persists, how it is investigated and distinguished from other causes of distress, and the range of approaches (environmental, behavioural, and pharmacological) that exist to support affected dogs.
Tail-Chasing in Dogs
Tail-chasing describes a pattern in which a dog repeatedly turns in tight circles, often trying to catch or bite their own tail. It can appear briefly during play or moments of high arousal in many dogs, but becomes a concern when it happens frequently, lasts for extended periods, or interrupts daily life. Some dogs chase their tail occasionally and stop when distracted; others may struggle to stop even when called, and a small number may injure the tail or surrounding skin through persistent biting or licking. Owners often arrive wondering whether what they are seeing is normal play, a behavioural habit, or a sign of discomfort. The distinction can be difficult to judge from the outside, because the movement itself looks similar across different underlying causes. Young dogs may spin during bursts of energy; older dogs may begin the behaviour suddenly after years of not doing it. The frequency, intensity, and difficulty of interruption tend to matter more than the presence of the behaviour alone. This page explores the signals that help distinguish different patterns of tail-chasing, the range of things that can drive or sustain the behaviour (from skin irritation and neurological changes to learned habits and compulsive disorders), and the ways the pattern can be investigated and approached. The goal is to help you understand what may be happening and what shape a conversation about your dog might take.
Trigeminal Neuritis
Trigeminal neuritis is a condition affecting the trigeminal nerves, the pair of cranial nerves (one on each side of the head) that control the muscles used to close the jaw. When these nerves become inflamed, dogs lose the ability to bring their jaw up normally, which often appears suddenly and can look quite dramatic: the mouth hangs open, and eating or drinking in the usual way becomes difficult or impossible. Owners most commonly notice that their dog's jaw has dropped and won't close, sometimes with drooling or difficulty picking up food. The tongue may hang out, and there may be concern about pain, choking, or whether the dog will be able to eat at all. Despite the striking appearance, many dogs remain alert and interested in food, though managing it becomes a mechanical challenge. This page explores the signals that may appear when these nerves are affected, what is understood about why inflammation occurs, how the condition is investigated and distinguished from other causes of jaw weakness, and the approaches used to support dogs while the nerve recovers. The course and outlook vary, and the page presents what is known about timeframes, complications, and the range of experiences owners may encounter.
Urine Marking in Cats
Urine marking is a form of communication that cats use to deposit small amounts of urine, usually on vertical surfaces, typically as a signal to other cats rather than to empty the bladder. It differs from ordinary urination in location, posture and purpose. Marked urine is often found on walls, furniture or doorways, and is delivered standing with a quivering tail. Owners commonly notice small wet patches on upright surfaces, a strong smell, or repeated soiling in the same spots, and may initially wonder whether their cat has a bladder problem or is simply avoiding the litter tray. Bladder disease can look similar. A cat, especially a male, that strains or makes repeated attempts to pass urine but produces little or none may have a blocked urethra. Home observation cannot show whether the bladder is blocked, and the time from complete blockage to death may be less than 24 to 48 hours. Marking can occur in response to stress, changes in the household, the presence of other cats, or reproductive behaviour in unneutered animals, though the pattern and trigger vary between individuals. It may appear suddenly or develop gradually, and can persist even when the original trigger has passed. This page explores the signals that may suggest marking rather than other causes of inappropriate urination, what is happening in the cat's social and emotional world, how the behaviour is investigated, and the range of approaches that exist to address it.
Vestibular Disease
Vestibular disease describes a disruption to the system that helps dogs and cats maintain balance, coordinate eye movements, and orient themselves in space. When this system is affected, animals may suddenly appear profoundly unsteady, as though the world has tilted beneath them. Owners often describe a head tilt, circling, loss of coordination, or eyes that flick rhythmically from side to side. The outward signs can look dramatic, but the underlying causes range widely. The vestibular system has components in both the inner ear and the brainstem, and problems can arise in either location. Some cases resolve on their own within days to weeks; others reflect conditions that require investigation and longer-term management. This page explores what vestibular signs may indicate, how the anatomy of balance works, what investigations can help clarify the picture, and the range of approaches used depending on what is found. The goal is to help you understand what you may be observing and what questions the clinical picture raises.
Metabolic Health
Acromegaly in Cats
Acromegaly is a condition in which the body produces too much growth hormone over a sustained period, typically due to a small tumour in the pituitary gland at the base of the brain. In cats, this excess hormone affects how tissues grow and how the body handles sugar, leading to a constellation of gradual changes that may not be obvious at first. Owners often notice that their cat seems larger or heavier than before, with a broader face, bigger paws, or a more prominent lower jaw. Many cats with acromegaly also develop diabetes that proves difficult to manage with insulin, or they may drink and urinate more than usual. The changes tend to unfold slowly, over months or years, and can be mistaken for normal ageing or weight gain. This page explores the signals that may prompt consideration of acromegaly, what is happening in the body to produce those changes, how the condition is investigated through blood tests and imaging, and the range of approaches that exist once a picture becomes clearer.
Acute Haemorrhagic Diarrhoea Syndrome (AHDS)
Acute haemorrhagic diarrhoea syndrome is a condition in which a dog develops sudden, profuse, bloody diarrhoea, often described as resembling raspberry jam, alongside vomiting and signs of feeling unwell. The cause remains uncertain, though it appears to involve inflammation and increased permeability of the intestinal lining, allowing fluid to shift rapidly out of the bloodstream and into the gut. It tends to occur without warning in otherwise healthy dogs, and the volume of fluid loss can be striking. Fluid loss can become severe within hours, and the condition can be fatal without treatment. Owners typically notice the sudden onset of severe, bloody diarrhoea, often with a characteristic bright red or dark red appearance, and the dog may seem quieter, less interested in food, or visibly uncomfortable. The condition can look alarming because of the volume and colour of the diarrhoea, and many owners arrive at this page trying to understand what they are observing and what may be happening inside. This page explores the signs that accompany acute haemorrhagic diarrhoea syndrome, the mechanisms thought to underlie it, how it is distinguished from other causes of bloody diarrhoea, and the approaches used to support affected dogs through recovery.
Acute Hepatic Failure
Acute hepatic failure occurs when the liver loses a large part of its working capacity over a short period, typically days rather than weeks. The liver performs hundreds of functions, so when enough of it stops working, many body systems are affected at once. This can follow exposure to toxins such as xylitol (a sugar-free sweetener found in many UK products, particularly dangerous to dogs), blue-green algae in still fresh water during warm weather, death cap mushrooms and some medications; infections such as leptospirosis; heatstroke; or cancer infiltrating the liver, though in some cases no clear cause is identified. Leptospirosis can pass to people, mainly through contact with the urine of an infected animal. Owners often notice a combination of signs that may at first seem unrelated: lethargy, loss of appetite, vomiting, diarrhoea, yellow-tinged gums or skin, confusion, or unusual behaviour. The liver is central to many processes, including metabolism, detoxification, protein production and clotting, so the pattern of illness tends to be complex and can develop quickly. This page explores the signals that may accompany acute hepatic failure, what is happening beneath those signs, how the condition is investigated, and the approaches used to support recovery. The content is intended to help you understand what you may be observing, not to diagnose or advise on an individual animal.
Acute Kidney Injury
Acute kidney injury describes a situation in which the kidneys suddenly lose much of their ability to filter waste from the blood. This can happen over hours or days, rather than the slow decline seen in chronic kidney disease. The kidneys may recover function if the underlying cause is identified and addressed, though the degree of recovery varies, and severe injury can be fatal within hours to days. Owners often notice a sudden change in how much their pet is drinking or urinating: sometimes much more than usual, sometimes very little. Appetite may drop sharply, and vomiting or listlessness can appear within a short window. The change tends to be abrupt enough that many owners can identify when things shifted. This page explores what signs may appear in the early stages, what mechanisms inside the kidney can lead to this kind of injury, how the condition is investigated through blood tests and imaging, and what approaches exist depending on the cause and severity. The focus is on understanding what acute kidney injury looks like and how it tends to unfold.
Addisons Disease in Dogs
A hormonal condition where the adrenal glands produce too little cortisol and often aldosterone, causing episodic weakness and illness and, in some dogs, a crisis that can progress to collapse within hours and be fatal without treatment.
Allium Toxicity (Onion and Garlic)
Allium toxicity refers to a form of poisoning that can occur when dogs or cats eat onions, garlic, leeks, chives, or related plants. These foods contain compounds that damage red blood cells in a way that causes them to break down more rapidly than usual. The effect is dose-dependent and cumulative, so toxicity can develop after a single large exposure or repeated smaller amounts over time. Owners most often arrive at this topic after their pet has eaten something containing onion or garlic, whether raw, cooked, powdered, or as an ingredient in human food, and they are wondering what signs to watch for or what the timeframe of concern might be. Some pets show no change at first, while others may develop lethargy, pale gums, dark urine, or reduced appetite in the days following exposure. This page explores the signals that may appear after allium exposure, the mechanism by which these plants affect red blood cells, the investigations that help assess the degree of anaemia or oxidative damage, and the range of approaches used to support affected animals depending on severity.
Anal Furunculosis (Perianal Fistulas)
Anal furunculosis is a condition in which the skin and deeper tissue around a dog's anus become inflamed, ulcerated, and develop tunnelling tracts called fistulas. The tissue breaks down in a way that creates openings and channels, often spreading around the anal area. It tends to be persistent, uncomfortable, and can significantly affect a dog's quality of life. German Shepherd Dogs are particularly prone, though other breeds can be affected. Owners most often notice signs like scooting, licking at the tail base, difficulty or reluctance when defecating, a foul odour, or visible raw, weeping areas around the anus. Some dogs become quieter or seem uncomfortable sitting. The visible changes can look alarming, and the condition often prompts worry about pain, infection, or what might be causing the tissue to break down in this way. This page explores what patterns may suggest anal furunculosis, what appears to be happening in the tissue and immune system, how the condition is investigated and characterised, and the range of approaches that exist, from topical and systemic treatments to dietary adjustments and surgical options. Each approach carries its own shape of benefit, burden, and uncertainty.
Anticoagulant Rodenticide Toxicity
Anticoagulant rodenticide toxicity occurs when a dog or cat ingests rat or mouse poison that interferes with the blood's ability to clot. These poisons work by blocking the recycling of vitamin K, which the body needs to produce several clotting factors. Without adequate clotting ability, bleeding can begin internally or from minor injuries, sometimes days after the exposure. Owners often arrive on this page because their pet has eaten bait they have seen, or because signs such as lethargy, pale gums, difficulty breathing, or visible bruising have appeared without obvious cause. In some cases the exposure is known; in others it is suspected based on what the animal is showing. Signs of bleeding typically appear about three to seven days after a toxic dose is eaten, with some variation between animals and with the amount eaten. This page explores the patterns that may be observed, the mechanism by which these poisons disrupt clotting, the investigations that help clarify what is happening, and the approaches used to manage exposure and support recovery.
Aspiration Pneumonia
Aspiration pneumonia describes inflammation and infection of the lung tissue that occurs when material from the mouth, throat, or stomach enters the airways instead of passing down the oesophagus or staying in the stomach. The inhaled material, which may include food, water, saliva, stomach contents, or vomit, carries bacteria and can directly irritate the delicate lining of the lungs, which can trigger infection as well as inflammation in the affected areas. Owners often notice sudden difficulty breathing, coughing, lethargy, or loss of appetite, particularly following an episode of vomiting, regurgitation, or anaesthesia. Some animals may have an underlying condition that makes aspiration more likely, such as weakness of the throat muscles, megaoesophagus, or recurrent vomiting. The severity varies widely: some animals show mild signs that improve quickly, while others develop severe respiratory distress. This page explores the signs that may raise concern, the mechanisms that allow material to enter the lungs, the tests used to confirm the diagnosis and assess severity, and the range of treatment approaches, including supportive care, antimicrobial therapy, and management of any underlying cause. Where aspiration has occurred once, understanding the reason helps inform whether steps to reduce future risk may be useful.
Atrial Fibrillation
Atrial fibrillation is a disturbance in the heart's rhythm in which the upper chambers (the atria) quiver rapidly and irregularly rather than contracting in a coordinated way. This irregular activity affects how efficiently blood moves through the heart, and it often leads to a fast, chaotic heartbeat that can be heard through a stethoscope or felt as an irregular pulse. Owners sometimes notice signs such as reduced energy, reluctance to exercise, faster breathing at rest, or episodes of weakness or collapse. In other cases, the irregular rhythm is discovered during a routine examination when no outward signs have been observed. Atrial fibrillation is more common in larger breed dogs, and it usually occurs alongside other heart disease, less often on its own. This page explores the signals that may be present, the mechanisms that lead to the rhythm disturbance, the investigations used to confirm and characterise it, and the range of approaches that exist for managing it over time.
Atrial Septal Defect
An atrial septal defect is an opening in the wall that normally separates the two upper chambers of the heart. In a healthy heart, this wall keeps oxygen-rich blood on the left side separate from oxygen-poor blood returning from the body on the right. When an opening exists, blood can flow between these chambers in ways it ordinarily would not, and over time this can alter how the heart and lungs work. Many dogs and cats with small openings show no outward signs, and the condition may be discovered during a routine examination when a heart murmur is heard. Others may develop reduced stamina or a reluctance to exercise as they grow. Faster or more laboured breathing at rest is a later sign that the heart is no longer coping. The pattern depends largely on the size of the opening and how much blood is crossing between the chambers. This page explores the signs that may bring an atrial septal defect to attention, the mechanisms by which an opening affects circulation and heart structure, the investigations used to confirm and characterise it, and the range of approaches that exist for managing it across a dog or cat's life.
Atypical Cushings in Dogs
Atypical Cushing's disease describes a pattern in which a dog shows signs often associated with Cushing's syndrome, such as hair loss, increased thirst and urination, or a pot-bellied appearance, but standard tests for cortisol excess come back normal. One long-standing theory is that in these cases the adrenal glands overproduce other steroid hormones, particularly sex-hormone intermediates such as 17-hydroxyprogesterone, androstenedione, progesterone, or oestradiol, rather than cortisol itself. The clinical picture can look identical to classic Cushing's, which is why owners and clinicians may pursue further investigation when initial screening does not explain what is being observed. This is an uncommon and debated label. The 2012 ACVIM consensus statement on diagnosing Cushing's in dogs concluded that sex hormones have not been proven to cause these signs, noted that only 14 published cases then met the definition, and suggested that some of these dogs may have mild classical Cushing's that current test cut-offs miss. A link between sex-hormone secretion and clinical signs has been documented for adrenal tumours, but not for pituitary-driven disease. A broader panel of adrenal steroid hormones, usually measured after ACTH stimulation, is sometimes used, but its specificity is low: raised values are common in dogs with other illnesses and in some dogs without adrenal disease. This page explores what an owner may observe, the mechanisms that may be at work beneath the surface, how the condition is investigated using extended hormone panels, and the medical and sometimes surgical approaches that exist. The aim is to provide context for conversations with your clinical team and to help you understand what may be happening when a familiar set of signs does not fit the usual diagnostic pathway.
Bile Duct Obstruction
Bile duct obstruction describes a blockage in the tubes that carry bile from the liver to the small intestine. Bile is a digestive fluid made continuously by the liver, and when its normal flow is interrupted, it can build up in the liver and spill into the bloodstream. This may happen suddenly or develop gradually, and the underlying cause can range from inflammation or infection to growths, stones, or structural changes in the ducts themselves. Owners most commonly notice a yellow tinge to the gums, skin, or the whites of the eyes, a sign that bile pigment is circulating in the blood rather than leaving the body as it should. Appetite may decline, and some animals become quieter or show discomfort in the abdomen. Urine can darken, and stools may become pale or clay-coloured when bile is no longer reaching the intestine. This page explores the patterns that may signal bile duct obstruction, what is happening inside the body when flow is interrupted, the imaging and laboratory tools used to investigate the ducts and liver, and the range of approaches, medical and surgical, that may be considered depending on the nature and location of the blockage.
Bile Peritonitis
Bile peritonitis describes inflammation of the membrane lining the abdomen (the peritoneum) caused by bile leaking into the abdominal cavity. Bile normally travels from the liver through a system of ducts to the gallbladder and small intestine, but rupture or leakage from any point along this pathway can allow bile to escape into the space around the abdominal organs. The presence of bile outside its usual channels tends to trigger significant inflammation and can alter fluid balance and metabolic function. Owners may observe signs that reflect abdominal discomfort or general unwellness. These can include reduced appetite, quiet behaviour, a tense or painful abdomen, or vomiting. The presentation often develops over hours to days, and the severity of signs can vary depending on the volume of bile, the site of leakage, and how the individual animal responds. Some animals may show subtle changes initially, while others appear more visibly unwell. Whether or not the leaked bile becomes infected, the picture can move from quiet and off food to collapse within hours. Older studies found infected leaks far more often fatal than sterile ones, but more recent studies have not found that difference, so a leak that turns out to be sterile is still a serious and potentially fatal problem. This page explores the signals that may prompt consideration of bile peritonitis, the mechanisms by which bile leakage occurs and affects the body, the investigations used to identify and characterise the condition, and the range of approaches that may be taken in different clinical contexts.
Bloat Without Torsion
Bloat without torsion describes a stomach that has filled with gas or fluid but has not twisted on itself. The stomach becomes enlarged and uncomfortable, often quite suddenly, but remains in its normal anatomical position. This is distinct from gastric dilatation-volvulus, in which the stomach both dilates and rotates, closing off its entrance and exit and cutting off its own blood supply. Untreated, that condition can lead to shock and death within hours. From the outside the two look alike, and it is a veterinary examination with abdominal radiographs that separates them. A stomach that has rotated a full 360 degrees can look similar to simple dilatation even on radiographs. Owners often notice a visibly swollen abdomen, restlessness, unproductive attempts to vomit, or signs of discomfort after eating. The dog may pace, stretch, or seem unable to settle. These signs can develop rapidly, and the degree of distress varies. Some dogs appear mildly uncomfortable, while others show more pronounced distress. These are also the signs of gastric dilatation-volvulus, and how mild or marked they look at home does not show whether the stomach has twisted. This page explores what bloat without torsion can look like when it first appears, what is happening inside the stomach and surrounding structures, how the condition is investigated, and what approaches exist to address it and reduce the chance of recurrence.
Blue-Green Algae Toxicity
Blue-green algae toxicity occurs when a dog or cat ingests water or material containing cyanobacteria, organisms that can bloom in ponds, lakes, and slow-moving water during warm months, particularly across the UK from late spring through early autumn. Some of these blooms produce toxins that can affect the liver, nervous system, or both, and the effect can unfold rapidly, sometimes within minutes to hours after contact with contaminated water. Owners most often arrive at this page after their animal has been near standing water that appeared discoloured, scummy, or carried visible streaks or mats, or after an episode of sudden vomiting, weakness, tremors, or collapse following a walk near water. Because the toxins vary in type and concentration, the pattern an owner observes may range from digestive upset to profound neurological signs, and an animal that looks normal can progress to collapse or breathing difficulty within minutes to a few hours, and liver-related signs can emerge over the following hours to days. This page explores what signs may appear and when, what is happening in the body when cyanotoxins are absorbed, how the exposure and its effects are investigated, and what approaches exist once an animal has been exposed.
Calcium Oxalate Urolithiasis
Calcium oxalate urolithiasis describes the formation of stones made of calcium oxalate crystals within the urinary tract, most often in the bladder, though they can also form in the kidneys or urethra. These stones develop when certain minerals become concentrated in the urine and precipitate out to form solid material. Once formed, they tend to remain and may grow over time, and they cannot be dissolved with diet or medication. Owners often notice signs related to difficulty or discomfort when urinating: frequent small amounts, straining, blood in the urine, or accidents in unusual places. In some cases, stones may be discovered incidentally during imaging for another reason, before any signs appear. Male dogs and cats can develop a blockage if a stone lodges in the narrow urethra, which in male dogs is most often just behind the small bone within the penis. A complete blockage presents as repeated attempts to urinate that produce nothing or only drops, often with crying out, restlessness and a tense, painful abdomen. Once urine cannot leave the bladder, waste products and potassium build up in the blood. Within roughly a day or two this can cause vomiting, weakness and disturbances of heart rhythm, and without relief of the blockage it can be fatal within about three days, sometimes sooner. Straining from an irritated bladder and straining from a blockage can look the same from the outside, and an overfull bladder cannot be reliably identified at home. This page explores the signals that may point towards stones, what happens at the metabolic and physical level to cause them to form, how they are identified through imaging and urine testing, and the range of approaches, from surgical removal to dietary adjustment, used to manage the condition and reduce the chance of recurrence.
Cannabis Toxicity
Cannabis toxicity occurs when a dog or cat ingests material containing THC (tetrahydrocannabinol), the psychoactive compound found in marijuana plants, edibles, oils, or discarded cannabis products. The substance affects the nervous system in ways that can produce a distinctive set of signs, though the severity and pattern vary depending on the dose, the form ingested, and the individual animal. Owners most commonly notice a sudden change in behaviour and coordination. Pets may appear unusually drowsy or unsteady, may dribble urine, or may startle easily at sounds or touch. Some animals become very still and seem disoriented, while others may twitch or show repetitive movements. The signs often develop within 1 to 2 hours of ingestion, and up to 4 hours in some dogs that had an empty stomach. Many owners arrive at this page uncertain whether what they are seeing fits a known pattern, or whether cannabis could explain what they are observing. This page explores the signs that can appear, what THC does in the body to produce those effects, how the condition is investigated when the history is unclear, and the range of approaches used to support affected animals while the compound clears. The focus is on helping you understand the shape of the problem and the logic behind how it is typically managed.
Cholangiohepatitis in Cats
Cholangiohepatitis in cats describes inflammation affecting the bile ducts and surrounding liver tissue. The bile ducts carry digestive fluid from the liver to the intestine, and when they become inflamed, the normal flow and function of bile can be disrupted. This can happen suddenly or develop more gradually over time. Owners often notice a cat becoming quieter, eating less, or losing weight. Some cats develop a yellow tinge to the gums or skin, and vomiting or changes in thirst may also appear. The pattern and severity of signs can vary considerably, and because the liver is involved in many body processes, the picture an owner observes may be subtle or quite pronounced. This page explores the signals that may point towards cholangiohepatitis, what may be happening in the liver and bile ducts to produce those signals, how the condition is investigated, and the range of approaches that exist depending on the underlying pattern and cause.
Cholelithiasis
Cholelithiasis refers to the formation of stones within the gallbladder, a small organ that stores bile produced by the liver. These stones form when components of bile, mainly calcium salts and bilirubin pigments, crystallise and accumulate over time. In dogs and cats, gallstones may exist without causing any outward signs, or they may contribute to episodes of abdominal discomfort, vomiting, jaundice, or changes in appetite and behaviour. Many owners first encounter this term after an ultrasound scan performed for another reason reveals stones incidentally, or when their pet develops signs that prompt investigation of the liver and biliary system. The clinical picture varies considerably depending on whether a stone remains static in the gallbladder or moves into a bile duct, and whether inflammation or obstruction develops as a result. This page explores the patterns that can bring cholelithiasis to light, the mechanisms underlying stone formation, the imaging and laboratory tools used to confirm and characterise the condition, and the range of approaches, from monitoring to surgical intervention, that may be considered depending on the individual animal's circumstances.
Chronic Hepatitis in Dogs
Chronic hepatitis in dogs describes ongoing inflammation in the liver that persists over weeks to months, gradually affecting how the liver works. The liver has a remarkable capacity to compensate, which means signs often emerge slowly and can be subtle at first. Examples are reduced appetite, occasional vomiting, increased thirst, or a general sense that a dog is not quite themselves. In some cases, jaundice (a yellowing of the gums or skin) appears, or fluid begins to accumulate in the abdomen. Owners often arrive at this page after blood tests have shown changes in liver enzymes, or because a dog has been losing weight or seems less energetic over time. The condition can have many underlying causes: some related to the immune system, some to copper accumulation and some to infections. In many cases the cause remains unclear even after investigation. This page explores the signs that may be observed, what is happening in the liver tissue itself, how chronic hepatitis is investigated through blood work and imaging, and the range of approaches that exist to support liver function and address underlying causes where they can be identified.
Chronic Kidney Disease in Cats
A progressive condition where kidney function declines over time, affecting fluid balance, waste filtration, and overall health.
Chronic Kidney Disease in Dogs
A progressive decline in kidney function that affects waste filtration, hydration, and metabolic balance over months to years.
Chronic Pancreatitis
Chronic pancreatitis describes ongoing inflammation in the pancreas that persists or recurs over time. The pancreas sits near the stomach and small intestine, producing enzymes that help digest food and hormones that regulate blood sugar. When inflammation becomes a long-term pattern, the normal tissue can be gradually replaced by scar tissue, which may affect how well the organ works. Owners often arrive at this page because their dog or cat has had repeated episodes of digestive upset (vomiting, reduced appetite, weight loss, or abdominal discomfort) that seem to settle and then return. In cats particularly, the signs can be subtle and build slowly over months. The condition can exist on its own or alongside other problems affecting the liver or intestines. This page explores the signals that may suggest chronic pancreatitis, what is happening in the tissue over time, how the condition is investigated through blood tests and imaging, and the range of approaches used to manage it. The goal is to help you understand what this diagnosis means and what shape care may take.
Chylothorax
Chylothorax is a condition in which lymphatic fluid, rich in fats from digested food, accumulates in the chest cavity around the lungs. This fluid, called chyle, normally travels through vessels from the intestines towards the bloodstream, but when that route is disrupted or overwhelmed, it can leak into the space between the chest wall and the lungs. The build-up makes it harder for the lungs to expand fully, and breathing can become laboured or rapid. Owners often notice their dog or cat breathing more quickly than usual, tiring easily, or standing with elbows out to make room for each breath. Some animals cough occasionally or seem quieter than normal. The signs tend to develop gradually, though they may appear to worsen suddenly if fluid accumulates more quickly. Chylothorax can occur on its own or alongside other conditions affecting the heart, lymphatic vessels, or chest. This page explores what patterns tend to prompt investigation, what may be happening beneath the surface, how the condition is identified and monitored, and what approaches exist for managing the fluid and addressing underlying causes where they can be found.
Cirrhosis in Dogs
Cirrhosis describes a state in which the liver has undergone widespread scarring, replacing normal tissue with fibrous bands and nodules that cannot carry out the organ's usual work. This scarring develops over time, often quietly, and by the point it becomes cirrhosis the damage is generally irreversible. The liver may still function for a period, but its reserve is reduced. Owners often arrive at this possibility after noticing signs that can seem unconnected at first: weight loss, a swollen abdomen, episodes of confusion or odd behaviour, or jaundice giving a yellow tint to the gums or skin. Sometimes the concern arises from blood test changes picked up during investigation of something else. The condition tends to be suspected in middle-aged to older dogs, though younger animals can be affected depending on the underlying cause. This page explores the patterns an owner may observe, what is happening inside the liver as scarring progresses, how cirrhosis is investigated and distinguished from other liver conditions, and the approaches available to support dogs living with it.
Colitis
Colitis describes inflammation of the large intestine, the final portion of the digestive tract where water is absorbed and stool takes its formed shape. When this lining becomes irritated or inflamed, the normal rhythm of absorption and movement changes, often producing softer stool, visible mucus, or small amounts of fresh blood. The urge to pass stool may become more frequent, and some animals strain even when little is produced. Owners typically arrive at this page after noticing changes in their pet's bowel habits: diarrhoea that seems to come from the back passage rather than higher up, jelly-like mucus coating the stool, or repeated trips to the garden with little result. The pattern can appear suddenly or build over days, and in some cases it resolves on its own while in others it persists or returns. This page explores the signals that point towards large bowel involvement, the range of causes that can trigger inflammation in this part of the gut, the ways these causes are investigated, and the approaches used to settle symptoms and address underlying triggers where they can be identified.
Constipation and Megacolon
Constipation describes difficulty passing faeces, or passing them less often than usual. Megacolon describes a colon that has become persistently dilated and has lost much of its ability to contract effectively. In cats with megacolon, the most common form is idiopathic megacolon, in which the smooth muscle of the colon wall itself appears to contract poorly, rather than megacolon simply being the end result of repeated constipation. Narrowing of the pelvic canal after a pelvic fracture has healed is another important cause, and nerve injury and dehydration contribute in some cats. Owners often notice straining in the litter tray, sometimes with little produced, or small, hard, dry stools appearing after several days. The posture is the same as that of a cat straining to pass urine. In a male cat, straining that produces no urine can be a urethral obstruction, which can cause death within 24 to 48 hours, and from outside the tray the two are often impossible to tell apart. Appetite may fall. In longer-standing cases, the abdomen may feel full, and some animals vomit or become visibly uncomfortable. This page explores what these patterns can look like, what may be happening in the colon and the systems that influence it, how the picture is investigated, and the range of approaches used to manage persistent constipation and megacolon.
Copper-Associated Hepatopathy
Copper-associated hepatopathy describes a group of conditions in which copper accumulates in the liver to levels that damage the tissue. Copper is a necessary trace element, but when the body cannot regulate or excrete it properly, whether because of an inherited defect in copper metabolism, dietary imbalance, or underlying liver disease, it builds up and becomes toxic to liver cells over time. Many dogs show no outward signs for months or years, and copper accumulation may be discovered incidentally during blood tests or investigation of vague signs such as reduced appetite, weight loss, or lethargy. In other cases, the liver damage progresses to cause more pronounced signs including jaundice (yellowing of the gums and whites of the eyes), vomiting, increased thirst, or fluid accumulation in the abdomen. Some breeds, particularly Bedlington Terriers, Labrador Retrievers, and Dobermanns, carry inherited variants that affect copper handling, though the condition appears across many breeds and in dogs without a known genetic predisposition. The page that follows explores what signs may prompt investigation, what happens inside the liver as copper accumulates, how the condition is diagnosed (including the role of biopsy and genetic testing) and the range of approaches used to manage copper levels and support liver function over time.
Cushings Disease in Dogs
A hormonal condition where the body produces excess cortisol, affecting skin, appetite, thirst, body shape, and energy regulation.
Diabetes Insipidus
Diabetes insipidus is a condition in which the body loses its ability to concentrate urine properly, leading to the production of large volumes of very dilute urine. This happens either because the brain does not produce enough of a hormone called antidiuretic hormone (ADH), or because the kidneys do not respond to it as they should. It is unrelated to diabetes mellitus, the more commonly known form of diabetes that involves blood sugar. Owners often notice their dog or cat drinking far more water than usual and urinating much more frequently, sometimes with accidents indoors or overnight. The urine itself tends to be very pale and watery. These patterns can develop quite suddenly or build gradually, and they may raise questions about kidney disease, behavioural change, or other metabolic conditions. This page explores the signals that may point towards diabetes insipidus, what is happening inside the body to cause them, how the condition is investigated and distinguished from other causes of increased thirst, and the approaches that exist for managing it over time.
Diabetes Mellitus in Cats
A metabolic condition involving impaired blood sugar regulation that may be influenced by weight, diet, and other health factors.
Diabetic Cataracts
Diabetic cataracts are a clouding of the lens inside the eye that occurs in dogs with diabetes mellitus. The lens becomes opaque because persistently high blood glucose triggers changes in the lens fibres, and this process can unfold remarkably quickly: in some cases within days to weeks, in others over weeks or months. An owner often notices a sudden or progressive whitening of one or both pupils, sometimes accompanied by clumsiness, reluctance to navigate stairs, or bumping into objects. Many dogs adapt to sight loss by relying on hearing and scent, and the loss of vision is often complete once both lenses are affected. A blind eye is not necessarily a comfortable one: a rapidly formed diabetic cataract can leak lens protein and inflame the eye, which shows as redness or squinting. This page explores what owners typically observe, the metabolic process that drives lens damage, how diabetic cataracts are distinguished from other causes of clouding, and the approaches that exist for managing vision loss or, in some cases, restoring sight. It does not tell you what your dog has, but it does map the landscape of what may be happening and what questions are worth exploring.
Eclampsia in Dogs
Eclampsia is a condition in which calcium levels in the blood drop rapidly, typically in the first few weeks after whelping when a dog is nursing puppies, and less often in late pregnancy or during whelping. The body's demand for calcium can outpace what is available in circulation, and this imbalance affects how nerves and muscles function. Owners often notice restlessness, panting or muscle tremors that appear suddenly in a nursing dog. Some dogs become unsteady or disoriented. Over a matter of hours these early signs can give way to stiffness, inability to stand, seizures and a high body temperature, and without calcium replacement the condition can lead to coma and death. How far the calcium has fallen cannot be judged from the signs at home. Small dogs and those nursing large litters are affected most often, though it can occur in any lactating dog. This page explores what the early signals of eclampsia can look like, the mechanism by which calcium depletion affects the body, how the condition is investigated, and the range of approaches used to address it.
Ectopic Ureters
Ectopic ureters are a developmental difference in the urinary tract, present from birth, in which one or both of the tubes that carry urine from the kidneys (the ureters) connect to the bladder or urethra in an unusual position. This altered anatomy can interfere with normal urine storage and release, and in many cases leads to urine leaking without the animal appearing to notice or strain. Owners often first observe persistent dampness around the vulva or prepuce, wet bedding, or a smell of urine on the coat, sometimes from a young age. The pattern can look different from typical house-training struggles because the leakage tends to be continuous or occurs during rest, rather than in discrete accidents. Some animals show no outward signs at all, and the anatomy is noticed only during investigation of a recurring urinary tract infection or imaging performed for another reason. This page explores the signals that may bring ectopic ureters to attention, the developmental and anatomical background, how the condition is investigated through imaging and other means, and the range of surgical and medical approaches that exist to manage it. The goal is to help you understand what may be occurring and what shape conversations about next steps might take.
Endocarditis
Endocarditis is an infection of the inner lining of the heart, most often affecting the heart valves. Bacteria that enter the bloodstream, sometimes from the mouth, skin, or urinary tract, can settle on valve tissue and begin to multiply, forming fragile clumps that interfere with the valve's ability to close properly. Over time, this can disrupt normal blood flow and allow pieces of infected material to break away and travel elsewhere in the body. The course varies widely. In some animals, signs build over weeks: a dog or cat may seem quieter than usual, lose interest in food, or run a fever. In others, particularly when the aortic valve is involved, the illness can progress over days, with sudden heart failure, bacteria spreading through the bloodstream, or infected clots lodging in a limb, the kidneys or the brain. In an older case series of 71 dogs, lameness was present in about half, clots lodging elsewhere in the body were suspected in 44 per cent, and many of the dogs did not survive. A new murmur is not always heard at first, and many of these signs cannot be told apart from other illnesses without an examination, blood tests and heart imaging. This page explores the patterns that may prompt investigation, the mechanisms by which infection takes hold in the heart, the ways the condition is identified, and the approaches used to manage it. It also covers Bartonella, a cause of endocarditis reported mainly in dogs in North America and not detected in the dogs tested in a UK case series of 77 dogs; Bartonella can also infect people.
Eosinophilic Bronchopneumopathy
Eosinophilic bronchopneumopathy is a condition in which a particular type of white blood cell, the eosinophil, accumulates in the airways and lung tissue, causing inflammation and difficulty breathing. It is recognised primarily in dogs, often in young to middle-aged animals, and usually builds gradually over weeks to months, although breathing difficulty can appear abruptly. Owners typically notice a persistent, harsh cough that often ends in gagging or retching, sometimes with faster or more effortful breathing, tiring on exercise or a nasal discharge. Most dogs otherwise remain bright and keep eating. Because the signs can resemble other respiratory conditions, the specific pattern of eosinophil involvement often becomes clear only through investigation. This page explores what may be observed at home, the underlying inflammatory process, how the condition is identified through imaging and samples from the airways, and the approaches used to manage the inflammation and support recovery.
Eosinophilic Enteritis
Eosinophilic enteritis is a pattern of inflammation in the small intestine in which a particular type of white blood cell, the eosinophil, accumulates in unusually high numbers within the intestinal wall. Eosinophils are part of the immune system and typically respond to parasites or allergens, but in this condition they gather in the gut lining in ways that can disrupt normal digestion and absorption. The underlying trigger is not always identified. Owners often notice recurring or persistent signs related to the digestive system: soft stools, diarrhoea, weight loss despite a normal appetite, or intermittent vomiting. The signs can develop gradually and may wax and wane over weeks or months. Because several other conditions can produce similar patterns, the path to identifying eosinophilic enteritis typically involves excluding other causes and, in many cases, examining a sample of intestinal tissue. This page explores the signals that may point towards this pattern of inflammation, the mechanisms that may drive it, the investigations used to distinguish it from other causes of chronic digestive upset, and the range of approaches (dietary, medical, or both) that are used to manage it over time.
Ethylene Glycol Toxicity
Ethylene glycol toxicity occurs when a dog or cat ingests antifreeze or certain other products containing this sweet-tasting chemical. Once absorbed, ethylene glycol is metabolised in the liver into compounds that can cause severe damage to the kidneys, among other effects. The window between ingestion and the development of serious metabolic changes tends to be short, often measured in hours rather than days. Owners most commonly arrive at this topic after a known or suspected ingestion: perhaps antifreeze has been spilled in the garage, or a pet has been found near a puddle of leaked coolant, which is often, though not always, brightly coloured. Early signs can include behaviour that appears similar to intoxication: unsteadiness, increased thirst, vomiting. Later signs may reflect worsening kidney function, though the progression and severity vary with the amount ingested and how quickly intervention occurs. This page explores the signs that may be observed, the metabolic processes that lead to kidney injury, how ethylene glycol exposure is investigated in practice, and the approaches used to interrupt the toxic pathway and support kidney function. The content is intended to help owners understand what may be happening and what shape the conversations and decisions ahead might take.
Exocrine Pancreatic Insufficiency (EPI)
Exocrine pancreatic insufficiency occurs when the pancreas fails to produce adequate digestive enzymes, resulting in malabsorption and characteristic signs of weight loss despite a voracious appetite.
Gallbladder Mucocele
A gallbladder mucocele describes a situation in which thick, gel-like bile accumulates inside the gallbladder, sometimes filling it completely. The gallbladder normally stores liquid bile produced by the liver, but in a mucocele, the bile becomes unusually viscous and can no longer flow freely. This can block the flow of bile and, in some dogs, the stretched gallbladder wall loses its blood supply, dies and ruptures, leaking bile into the abdomen (bile peritonitis), which is life-threatening. Many dogs with a mucocele show no outward signs at all, and the finding may appear during imaging performed for another reason. When signs do occur, they often include reduced appetite, quietness, vomiting, or discomfort in the abdomen. Some owners notice a yellow tinge to the gums, skin or whites of the eyes (jaundice), which in a dog with a mucocele points to bile no longer draining normally. The picture can range from subtle and long-standing to sudden and severe when the gallbladder wall fails, and the condition tends to be identified in middle-aged to older dogs, with certain breeds appearing more frequently in case series. This page explores what may be observed at home or during examination, the mechanisms that contribute to mucocele formation, the imaging and laboratory methods used to investigate it, and the range of approaches (medical and surgical) that may be considered depending on the individual presentation.
Gastric Ulceration
Gastric ulceration describes erosions or breaks in the protective lining of the stomach, exposing the tissue beneath to digestive acid. These lesions can range from superficial damage to deeper wounds that may bleed or, in some cases, perforate the stomach wall. Owners often arrive at this page because their dog or cat has been vomiting, sometimes with fresh blood or dark, digested blood that resembles coffee grounds. Other times the concern is less specific: reduced appetite, signs of nausea, weight loss, or dark tarry stools that suggest bleeding higher in the digestive tract. In some animals, ulceration is discovered incidentally during investigation of another condition, without obvious signs at home. This page explores the patterns that may raise suspicion, the mechanisms that allow ulcers to form, the ways they are identified through examination and imaging, and the range of approaches used to support healing and manage underlying causes.
Gastroenteritis in Cats
Gastroenteritis describes inflammation of the stomach and intestines. It is one of the most common reasons cats vomit, have diarrhoea, or show less interest in food. The inflammation disrupts normal digestive function, and the signs an owner observes reflect that disruption. Many cats experience brief, self-limiting episodes after dietary indiscretion or minor viral infection. Others develop gastroenteritis as part of a chronic pattern, linked to food sensitivity, inflammatory bowel disease, or other underlying conditions. What an owner sees at home (the frequency of vomiting, the character of the stool, and changes in appetite or demeanour) offers clues to the severity and likely cause. This page explores the signs that may be observed, the mechanisms and causes that can drive gastroenteritis, the investigations that help distinguish one cause from another, and the range of approaches used to manage both acute and ongoing cases.
Giardiasis
Giardiasis is an infection of the intestine caused by a microscopic parasite called Giardia. The parasite lives in the small intestine and can interfere with the normal absorption of nutrients and water, though many infected animals, dogs in particular, show no outward signs at all. When signs do appear, they most often take the form of soft, pale, poorly formed stool containing mucus, sometimes with a greasy appearance and a strong odour; watery diarrhoea is unusual. Owners typically arrive on this page because they have noticed a change in their pet's stool consistency that has persisted, or because a faecal test has returned a positive result for Giardia and they are trying to understand what that means. In young animals or those in multi-pet households, the question often centres on whether the infection explains ongoing digestive upset, and what the implications may be for other animals or people in the home. This page explores the signs that can accompany giardiasis, the mechanisms by which the parasite affects the gut, the ways in which infection is identified in practice, and the range of approaches used to address it. It also considers the contexts in which Giardia is found, the variability in how different animals respond, and the factors that shape decisions around testing and intervention.
Glomerulonephritis
Glomerulonephritis describes inflammation of the glomeruli: the tiny filtering units inside the kidneys that clean the blood and produce urine. When these filters become inflamed, they may leak protein into the urine or allow waste products to build up in the bloodstream, and in some cases both processes occur together. The condition can develop suddenly or progress quietly over months, and the underlying cause is not always apparent at the time it is recognised. Owners often arrive at this page after routine bloodwork or urine testing has shown changes such as protein in the urine, elevated kidney values, or low albumin in the blood. Some dogs or cats show visible signs such as reduced appetite, weight loss, or swelling in the legs or abdomen, while others appear well and the findings emerge during screening for another concern. The pattern of signs depends on how much the filtering function has been affected and whether the condition has triggered secondary changes elsewhere in the body. This page explores what glomerulonephritis may look like in daily life, what processes underneath can lead to inflammation of the kidney filters, how the condition is investigated through blood tests, urine analysis, and sometimes tissue sampling, and the range of approaches that exist to address the inflammation, support kidney function, and manage complications that may develop over time.
Grape and Raisin Toxicity in Dogs
Grapes, raisins, sultanas and currants can cause sudden kidney injury in some dogs. Tartaric acid is thought to be the toxic substance, though why only certain dogs are affected remains incompletely understood. The reaction, when it occurs, typically begins within hours of ingestion and can progress quickly. Not every dog that eats grapes will become ill, but there is currently no way to predict which individuals will react. Owners most often arrive at this page after discovering their dog has eaten grapes, raisins, or foods containing them, perhaps from a fruit bowl, a dropped snack, or baked goods. Early signs, when present, may include vomiting, diarrhoea, reduced appetite, quiet behaviour, or changes in thirst and urination. Some dogs show no outward signs at all in the first hours, and looking well at that stage does not show that the kidneys have been spared. This page explores the patterns that may suggest exposure or early kidney involvement, what is understood about how the injury develops, the investigations that help assess kidney function, and the range of approaches used to limit absorption, support the kidneys, and monitor recovery. The goal is to help you understand what may be unfolding and what shape the veterinary response typically takes.
Heartworm Disease in Cats
Heartworm disease in cats occurs when parasitic worms transmitted by mosquitoes settle in the blood vessels of the lungs and, less commonly, the heart. Unlike in dogs, where large numbers of adult worms may develop, cats typically harbour only a few worms, and many infections resolve without the worms reaching maturity. The condition behaves differently in cats than in dogs, and even a small worm burden can trigger significant inflammatory reactions in the lungs. Owners often arrive at this topic because their cat has developed respiratory signs (coughing, difficulty breathing, or episodes that resemble asthma) or because heartworm has been mentioned as a possibility during investigations for these signs. In some cases, cats show vague signs such as reduced appetite, weight loss, or vomiting, or the condition is discovered incidentally during testing for other reasons. Collapse or death can occur suddenly and without warning, including in cats that had appeared healthy. This page explores what signs may be observed, what is happening in the lungs and heart when heartworm is present, how the condition is investigated, and what approaches exist for managing affected cats and reducing future risk.
Helicobacter Gastritis
Helicobacter gastritis describes inflammation of the stomach lining associated with Helicobacter bacteria, spiral-shaped organisms that can colonise the gastric mucosa in dogs and cats. These bacteria are found in many healthy animals without causing problems, but in some cases their presence appears linked to ongoing stomach inflammation. Why this happens in some animals and not others is not known. Owners often arrive at this topic after their pet has shown signs like intermittent vomiting, reduced appetite, or occasional nausea over weeks or months, and investigations have identified Helicobacter organisms in stomach samples. The connection between finding the bacteria and explaining the signs can feel uncertain, because not all animals with Helicobacter develop symptoms, and not all gastritis involves Helicobacter. This page explores what patterns may suggest Helicobacter-associated inflammation, what is understood about how these bacteria interact with the stomach lining, how the condition is investigated through endoscopy and biopsy, and what treatment approaches exist, including their limitations and the questions that often remain even after testing.
Hepatic Lipidosis
Hepatic lipidosis describes a state in which fat accumulates inside liver cells to the point where the liver struggles to function normally. It develops most commonly in cats, typically after a period of not eating, sometimes only a few days, and often follows a stressful event, illness, or abrupt change in routine. The underlying trigger may be obvious or subtle. Owners often notice their cat has stopped eating, appears lethargic, and may begin to show a yellow tinge to the skin, gums, or whites of the eyes. Weight loss tends to be noticeable, though the cat may have been overweight beforehand. Vomiting or excessive drooling can occur, and some cats seem uncomfortable or reluctant to move. This page explores the signals that can appear, what is happening inside the liver and why fat builds up in this way, how the condition is investigated through blood tests and imaging, and the range of approaches used to support recovery. The focus throughout is on helping you understand the shape of the condition and the decisions that may follow.
Hydronephrosis
Hydronephrosis describes swelling of the kidney that occurs when urine cannot drain away normally. The kidney's collecting system (the part that funnels urine towards the ureter and bladder) becomes stretched and enlarged under the pressure of backed-up fluid. This can affect one kidney or both, and may develop suddenly or over weeks to months. Many owners first encounter this term after imaging arranged for other reasons, or when investigating changes such as reduced appetite, weight loss, or discomfort that can accompany kidney problems. In some cases there are no outward signs at all, and the finding is incidental. The degree of swelling does not always match what an animal appears to feel, and the impact on kidney function depends on how complete the blockage is, how long it has been present, and whether the other kidney is working normally. This page explores the patterns that can prompt investigation, what may be causing the obstruction or pressure, how hydronephrosis is identified and monitored, and the range of approaches that exist depending on the underlying cause and the degree of kidney involvement.
Hyperlipidaemia
Hyperlipidaemia describes a persistent elevation of fats in the bloodstream, chiefly triglycerides and cholesterol. In dogs and cats, this can occur as a secondary response to other conditions such as endocrine disease or pancreatitis, or in some cases as a primary inherited tendency. It may be discovered incidentally on routine blood testing, or it may be accompanied by visible changes such as cloudiness in the eyes, skin lesions, or gastrointestinal signs. Many animals with hyperlipidaemia show no outward signs at all, particularly in the early stages. When signs do appear, they vary widely depending on the underlying cause and the degree of lipid elevation. Some owners first learn of it when a blood sample drawn for testing looks milky or opaque. This page explores the observable signals that may accompany hyperlipidaemia, the metabolic processes that lead to lipid accumulation, the investigations used to characterise the pattern and identify contributing factors, and the range of dietary and medical approaches that may be considered in managing the condition.
Hyperparathyroidism in Dogs
Hyperparathyroidism describes a pattern in which the parathyroid glands (small structures near the thyroid in the neck) produce too much parathyroid hormone. This hormone normally regulates calcium levels in the blood, and when present in excess, it can pull calcium from bone and raise the amount circulating in the bloodstream. The condition can develop on its own (primary hyperparathyroidism, often linked to a small benign growth on one of the glands) or as a response to another process, such as kidney disease or dietary imbalance (secondary hyperparathyroidism). Owners may notice increased thirst and urination, straining to urinate or blood in the urine, reduced appetite, occasional vomiting, or a general loss of energy. Some dogs show no outward signs at all, and the pattern is identified only when blood tests reveal elevated calcium during routine screening or investigation of another concern. The signs, when present, tend to develop gradually and can be subtle in the early stages, although a stone blocking the urethra causes straining with little or no urine and is life-threatening. This page explores what hyperparathyroidism may look like in a living dog, the mechanisms that drive changes in calcium and bone, how the condition is investigated through blood tests and imaging, and the range of approaches used depending on the underlying cause and the degree of disturbance.
Hyperthyroidism in Cats
A condition where the thyroid gland produces excess hormone, increasing metabolic rate and affecting weight, appetite, and organ function.
Hypertrophic Pyloric Gastropathy
Hypertrophic pyloric gastropathy describes a thickening of the pylorus, the muscular ring that controls the passage of food from the stomach into the small intestine. When this tissue becomes thickened, the opening can narrow, and the normal flow of digested material may be slowed or partially obstructed. This tends to occur more often in certain small breeds, and signs often develop gradually over weeks to months. Owners typically notice vomiting that occurs some hours after eating, often containing undigested or partially digested food. The vomiting may be intermittent at first, and appetite often remains normal in the early stages. Weight loss or a failure to maintain body condition often develops over time as less food is able to pass through into the intestine. This page explores the patterns that may be observed, the mechanisms that can lead to pyloric thickening, the investigations used to assess the stomach and pylorus, and the range of approaches, both medical and surgical, that may be considered depending on the individual case.
Hypothyroidism in Cats
Hypothyroidism in cats occurs when the thyroid gland produces less thyroid hormone than the body needs. This hormone influences how cells use energy, so when levels drop, many processes in the body can slow down. In cats, this condition is uncommon and tends to appear in specific contexts: most often after treatment for an overactive thyroid, and only rarely as a primary gland problem. Owners may notice changes that develop gradually: reduced activity, reduced appetite, weight gain in some cats, a dull or matted coat, or a cat that seeks warmth more than usual. Because thyroid hormone affects many systems, the signs can be subtle and easily attributed to other causes, particularly in older animals. Some cats show few outward changes and the condition is identified during investigation of something else. This page explores the patterns that may suggest low thyroid function, what is happening at a glandular and cellular level, how the condition is investigated through blood tests and clinical assessment, and the approaches available once a picture emerges. The aim is to help you understand what hypothyroidism in cats can look like and how it is typically approached.
Hypothyroidism in Dogs
Hypothyroidism is a condition in which the thyroid gland produces less thyroid hormone than the body needs. Thyroid hormone influences metabolic rate in nearly every tissue, so when levels fall, many body systems tend to slow down. In dogs, the most common underlying cause is lymphocytic thyroiditis (an immune-mediated process in which the body's own immune cells gradually damage the thyroid tissue), though the gland can also be affected by atrophy of unknown cause, and rarely by other processes. Owners often notice a gradual change in energy, weight, coat quality, or behaviour. A dog may become less playful, gain weight despite no change in food, develop a dull or thinning coat, or seek out warm places more than before. Because the signs accumulate slowly and can be subtle, they are sometimes attributed to age or temperament, and the pattern may only become clear in hindsight. Certain breeds carry higher genetic risk, particularly through specific dog leukocyte antigen (DLA) haplotypes associated with autoimmune thyroiditis. This page explores what hypothyroidism can look like across different body systems, the mechanisms that lead to low thyroid hormone, how the condition is investigated through blood tests and clinical assessment, and the landscape of approaches used to restore thyroid hormone levels and support long-term metabolic health.
Idiopathic Pulmonary Fibrosis in West Highland White Terriers
Idiopathic pulmonary fibrosis is a progressive condition in which the delicate tissue of the lungs becomes thickened and scarred over time, making it harder for oxygen to pass into the bloodstream. In West Highland White Terriers, this pattern appears more frequently than in other breeds, though the underlying trigger remains unknown. The scarring tends to be gradual and irreversible. Owners often notice a cough that persists over weeks or months, sometimes accompanied by faster breathing or reduced stamina during walks. The signs can be subtle at first and may be mistaken for other respiratory conditions. Some dogs show these changes in middle age, while others remain unaffected until later in life. This page explores what signs may be observed, what is understood about the changes occurring in the lung tissue, how the condition is investigated through imaging and other tests, and what approaches exist to ease symptoms and support quality of life. The course varies between individuals, and the information here is intended to support understanding rather than predict what will happen in a particular dog.
Ileus
Ileus describes a state in which the normal, rhythmic movements of the intestines slow down or stop, without a physical blockage being present. The bowel itself is open, but the muscular contractions that push food, fluid, and gas along the digestive tract become weak or absent. This can occur after surgery, alongside certain metabolic disturbances, or in response to pain or inflammation elsewhere in the abdomen. Owners most often notice signs that suggest the digestive system has stalled: reduced appetite, bloating, discomfort, vomiting, or an absence of normal bowel movements. These signs can develop gradually or appear quite suddenly, and the pattern varies depending on which part of the intestine is affected and what triggered the slowdown. The same signs occur with a physical blockage of the bowel and, in dogs, with gastric dilatation-volvulus (a twisted stomach), both of which are life-threatening and can worsen over hours, and ileus cannot be told apart from them at home. This page explores the signs that may accompany ileus, the mechanisms that can cause the bowel to lose its movement, how the condition is investigated, and the range of approaches used to support recovery. Each case unfolds differently, and the page is intended to help you understand what may be happening and what questions may be worth exploring.
Intestinal Intussusception
Intussusception describes a telescoping of the intestine, where one segment slides inside the adjacent portion in the way a collapsible telescope folds into itself. This disrupts the normal passage of food and fluid, compresses blood vessels within the bowel wall, and can progress to death of the affected bowel wall, leakage of gut contents into the abdomen and sepsis if the blood supply is compromised for long enough. Most clinically significant intussusceptions do not unfold on their own and are corrected surgically. Owners most often notice vomiting, reduced appetite, and sometimes blood-stained or dark stool, though the pattern and severity vary depending on where along the intestine the telescoping occurs and how completely it obstructs the lumen. The condition occurs more frequently in young animals, particularly following episodes of gastroenteritis or parasitic infection that alter normal intestinal movement, and German Shepherd Dogs appear over-represented in some clinical case series, though it can occur in any breed at any age. This page explores what an owner may observe, the mechanisms that lead to telescoping, how the condition is investigated through imaging and physical examination, and the approaches used to address it, including the role of surgery and the factors that influence outcome.
Intestinal Lymphangiectasia
Intestinal lymphangiectasia is a condition in which the lymphatic vessels inside the wall of the intestine become abnormally widened and dilated. These vessels normally carry protein-rich fluid away from the gut, but when they are dilated or blocked, they leak lymph into the intestinal lumen. The result is that protein, particularly albumin, is lost into the gut and passed out in faeces, rather than being retained in the bloodstream. Owners most often notice soft or watery diarrhoea, gradual weight loss, or a swollen abdomen. In some animals the coat becomes dull or the paws and limbs appear puffy. The condition can develop gradually, or signs may appear more suddenly. Fast or laboured breathing, trembling or seizures are signs of serious complications that cannot be assessed at home. It can occur at any age. Certain breeds, including Yorkshire Terriers, Soft Coated Wheaten Terriers and Norwegian Lundehunds, are seen more frequently, though any dog may be affected. This page explores what an owner might observe, what is happening beneath those signs, how the condition is investigated through blood tests and imaging, and the dietary and medical approaches that exist to support dogs living with intestinal lymphangiectasia.
Liver Disease in Dogs
Liver disease describes any condition in which the liver is not working as it should. The liver processes nutrients, filters waste from the blood, produces proteins needed for clotting, and stores energy. When it is damaged or failing, these functions can be disrupted in ways that affect the whole body. Owners often arrive at this page because their dog has become quieter than usual, is eating less, has lost weight, or has developed vomiting or diarrhoea. Some notice a yellow tinge to the gums or whites of the eyes, or that their dog is drinking and urinating more than normal. In many cases, the possibility of liver involvement emerges after blood tests taken for another reason. This page explores what liver disease can look like in dogs, what may be happening inside the liver itself, how the condition is investigated through blood work and imaging, and the range of approaches that may be considered depending on the underlying cause and stage.
Lymphoplasmacytic Enteritis
Lymphoplasmacytic enteritis describes a pattern of persistent inflammation in the small intestine, where particular types of immune cells (lymphocytes and plasma cells) gather in numbers higher than usually seen in healthy tissue. This inflammation can interfere with how the gut absorbs nutrients and how comfortably it moves food through. It sits within a broader group of conditions sometimes called inflammatory bowel disease, though that term is used differently across contexts. Owners often arrive at this page because their dog or cat has been experiencing ongoing digestive signs: loose stools, weight loss despite eating, occasional vomiting, or a coat that has lost condition. These signs tend to build gradually rather than appearing suddenly, and they may come and go over weeks or months. The condition is confirmed through biopsy, not through symptoms alone, so many owners are seeking to understand what the diagnosis means and what has been found in their pet's tissue. This page explores the signals that can appear in affected animals, the mechanisms that may drive the inflammation, the investigations used to reach and refine the diagnosis, and the range of approaches (dietary, medical, and supportive) that may be considered in managing the condition over time.
Megaoesophagus
Megaoesophagus involves dilation and loss of normal muscular function of the oesophagus, causing food to accumulate rather than passing normally to the stomach, with regurgitation as the hallmark sign.
Megaoesophagus in Cats
Megaoesophagus describes a condition in which the oesophagus (the muscular tube that carries food from the mouth to the stomach) loses its ability to move food along effectively. Instead of the normal coordinated waves of contraction that push food downward, the oesophagus becomes enlarged and floppy, and food tends to collect in it rather than reaching the stomach. This can happen from birth or develop later in life. Owners often notice regurgitation: food or liquid comes back up shortly after eating, sometimes undigested and without the forceful effort seen with vomiting. Cats may lose weight over time, and some develop coughing or difficulty breathing if regurgitated material enters the airways. The pattern can be intermittent at first, or present consistently from kittenhood, depending on the underlying cause. This page explores the signs that may prompt concern, the mechanisms that can lead to megaoesophagus, how the condition is investigated, and the range of approaches used to support affected cats. The focus is on understanding what may be happening and what questions tend to arise during the diagnostic and management process.
Nephrotic Syndrome
Nephrotic syndrome describes a pattern in which the kidneys lose large amounts of protein into the urine, enough to lower protein levels in the bloodstream and trigger a cascade of changes throughout the body. This protein loss is typically caused by damage to the filtering units within the kidney, though the underlying reason for that damage can vary. Owners often first notice swelling (around the abdomen, under the skin, or sometimes around the legs) alongside changes in appetite, energy, or the appearance of the urine itself. In some cases, the condition is identified through routine blood or urine tests before visible signs appear. The swelling and other features arise not from kidney failure in the traditional sense, but from the body's response to losing protein it normally retains. This page explores the signs that can suggest nephrotic syndrome, the mechanisms that drive protein loss and fluid shifts, the investigations used to characterise the pattern and search for underlying causes, and the range of approaches available depending on what is found.
Obesity in Dogs
A condition of excess body fat that increases mechanical stress on joints and alters metabolic, cardiovascular, and respiratory function.
Ovarian Remnant Syndrome
Ovarian remnant syndrome describes a situation in which a female dog or cat who has been spayed continues to show signs associated with an active ovary. This typically happens when a small piece of ovarian tissue, sometimes only a few millimetres across, is unintentionally left behind during the spay procedure and remains functional, continuing to produce hormones. Owners often notice behaviours or physical changes they associate with being in season: a female dog may attract male dogs, show vulval swelling, or display behavioural changes, while a female cat may call, adopt mating postures, or show restlessness. These signs can appear weeks, months, or occasionally years after the spay, and the timing often surprises owners who assumed the surgery was complete. This page explores what these signals can look like in practice, the biological mechanism that allows remnant tissue to function, how the condition is investigated when suspected, and the range of approaches that exist once a remnant is identified.
Pancreatitis in Cats
An inflammatory condition of the pancreas in cats that often presents subtly, may occur alongside other organ conditions, and can be life-threatening in its severe acute form.
Pancreatitis in Dogs
An inflammatory condition of the pancreas that causes abdominal pain and digestive disruption, and ranges from mild to life-threatening.
Patent Ductus Arteriosus
Patent ductus arteriosus is a condition in which a blood vessel that normally closes soon after birth remains open. Before a puppy or kitten is born, a short vessel called the ductus arteriosus connects two of the large arteries leaving the heart, allowing blood to bypass the lungs while they are not yet functioning. In most animals, this vessel closes within the first week of life; when it does not, blood continues to flow through it in a pattern that places extra strain on the heart and lungs. Owners most commonly encounter this condition when a murmur is detected during a routine puppy or kitten check, often before any signs are apparent. In some cases, an animal may show reduced energy, slower growth, or changes in breathing pattern as the heart begins to work harder. The condition occurs more frequently in certain breeds, and the severity of signs depends largely on how much blood is moving through the open vessel. This page explores the signals that may bring this condition to attention, the mechanisms by which the open duct affects circulation and heart function, the investigations used to confirm and characterise it, and the range of approaches that exist for managing it.
Persistent Right Aortic Arch
Persistent right aortic arch is a structural difference present from birth in which a blood vessel that normally disappears during development remains and forms a ring around the oesophagus. This ring can press on the oesophagus, making it difficult for food to pass normally into the stomach. The condition is one of several vascular ring anomalies, and it tends to become noticeable when a puppy begins eating solid food. Owners often first observe regurgitation shortly after meals, typically in young animals during or just after weaning. The puppy may bring back undigested food, sometimes in a tubular shape, and may seem hungry again soon afterwards. Some animals grow more slowly than their littermates, and signs can range from occasional episodes to more persistent difficulty with eating. This page explores the signals that may prompt consideration of this condition, the anatomical basis for those signals, the imaging and other investigations used to clarify the diagnosis, and the surgical and supportive approaches that may be discussed. The goal is to help you understand what may be happening and what questions may be useful as the picture becomes clearer.
Phaeochromocytoma
A phaeochromocytoma is a tumour that arises from specialised cells in the adrenal gland, a small organ that sits near the kidney and produces hormones involved in stress response and blood pressure regulation. When these cells become tumorous, they often release excessive amounts of adrenaline and related hormones into the bloodstream, which can affect how the body responds to everyday activity or stress. Owners often arrive on this page because their dog has shown episodes of collapse, restlessness, increased panting, or unexpectedly high heart rate, or because a mass near the kidney has been found during imaging for something else. The signs tend to be episodic rather than constant, and in many cases the tumour is discovered incidentally when investigating another concern. Historically no consistent breed predisposition was recognised, though a 2025 UK-wide VetCompass study found Soft-Coated Wheaten Terriers, German Pointers, and Miniature Schnauzers to be significantly more likely to be diagnosed than crossbred dogs; in the same study 70.7% of affected dogs were male, and neutered males had about twice the odds of diagnosis of entire males. Most affected dogs are middle-aged or older. This page explores what an owner may observe, the mechanisms that produce those signs, how the condition is investigated through imaging and hormone measurement, and the surgical and medical approaches that exist. It also outlines what is understood about behaviour over time, both with and without intervention.
Phimosis and Paraphimosis
Phimosis and paraphimosis are conditions affecting the penis in male dogs, involving the prepuce, the fold of skin that normally covers and protects the penis when it is not erect. Phimosis describes a situation where the opening of the prepuce is too narrow for the penis to emerge normally, whilst paraphimosis refers to the penis being unable to retract back inside the prepuce after it has extended. Owners most commonly notice paraphimosis after mating or an erection, when the penis remains exposed and the prepuce forms a constricting band behind the bulbus glandis. The exposed tissue swells rapidly and may appear dry or discoloured, and the changes progress over hours rather than days. Phimosis tends to be recognised more gradually, often when a young dog matures or if difficulty with urination or discharge is observed. This page explores the signals that may be present with each condition, the anatomical and physiological factors that contribute to them, how they are investigated in practice, and the range of approaches, from conservative management to surgical intervention, that may be considered depending on severity and underlying cause.
Pleural Effusion
Pleural effusion describes a situation where fluid accumulates in the space between the lung and the chest wall, a narrow gap that normally contains only a thin film of lubricating fluid. When this space fills beyond that baseline, it can compress the lungs and make breathing more effortful. Owners often notice changes in breathing pattern: faster, shallower breaths, reluctance to lie down, or a posture with elbows held away from the body. The fluid itself has no single cause: it can arise from heart conditions, infection in the chest, tumours, bleeding, leaking of lymphatic fluid, or, less often, low blood protein. The character of the fluid and the reason it has formed tend to shape both the investigation and the approach that follows. This page explores the signs that may prompt concern, the mechanisms that can lead to fluid accumulation, the methods used to investigate the type and cause of the effusion, and the range of approaches that may be considered depending on what is found.
Polycystic Kidney Disease in Cats
Polycystic kidney disease is an inherited condition in which fluid-filled pockets (cysts) develop within the kidney tissue over time. These cysts gradually enlarge and multiply, slowly replacing the normal working tissue of the kidney. The condition is present from birth, but signs typically emerge in middle age as the cysts occupy more space and the kidneys begin to lose function. Many cats show no outward signs for years. When changes do appear, they often reflect the kidney's declining ability to filter waste and regulate fluid balance: weight loss, increased thirst, changes in appetite, or a generally quieter demeanour. Some owners notice the condition through routine imaging or blood work before any signs are visible at home. This page explores the patterns an owner may observe, what is happening inside the kidney as cysts develop, how the condition is identified and monitored, and the range of approaches used to support kidney function and quality of life over time.
Portosystemic Shunt
A portosystemic shunt is an abnormal blood vessel that allows blood from the intestines and other abdominal organs to bypass the liver. Normally, this blood travels through the liver first, where toxins are filtered and nutrients are processed. When a shunt is present, unfiltered blood flows directly into the general circulation, and the liver itself may remain underdeveloped. Owners often arrive at this page because their young dog or cat has been slow to grow, seems unusually quiet or uncoordinated after meals, or has had episodes of confusion, drooling, or apparent disorientation. Some animals show digestive signs (vomiting, diarrhoea, or poor appetite), while others may have urinary tract problems or subtle behavioural changes that come and go. The pattern can be vague at first, and the pieces may only connect over time. This page explores the signals that can accompany a portosystemic shunt, the mechanisms that produce those signals, how the condition is investigated through blood tests and imaging, and the medical and surgical approaches that exist. The goal is to help you understand what may be happening and what shape the pathway forward can take.
Prostatic Hyperplasia
Prostatic hyperplasia refers to non-cancerous enlargement of the prostate gland, which sits just behind the bladder, in entire (uncastrated) male dogs. This enlargement happens as a normal consequence of hormonal influence over time, and tends to develop gradually in most uncastrated males as they age. The prostate tissue responds to testosterone and related hormones by increasing in size. The change is benign, though small fluid-filled cysts often form within the gland as it ages. The signs most often seen are blood in the urine and blood dripping from the prepuce when the dog is not urinating. Some dogs also strain to pass faeces or pass ribbon-shaped stools. Many dogs show no outward signs at all, and the enlargement is identified during examination for another reason. The size of the prostate does not always correspond to the severity of signs; a moderately enlarged gland may cause significant difficulty, while a larger one may cause none. This page explores what an owner may observe, the hormonal and structural changes occurring in the gland, how prostatic hyperplasia is investigated and distinguished from other prostatic conditions, and the range of approaches available for managing it. These approaches vary in how quickly they work, their permanence, and their suitability depending on whether the dog is used for breeding.
Protein-Losing Enteropathy
Protein-losing enteropathy describes a group of conditions in which the lining of the intestine loses its ability to hold onto protein, allowing protein from the blood and lymph to leak into the gut, where it is lost. This ongoing loss can lead to falling protein levels in the blood, which may show up as weight loss, fluid accumulation in the belly or limbs, or recurring digestive upset. Owners often arrive at this page after noticing persistent diarrhoea, a swollen abdomen, or gradual weight loss despite a normal appetite. In some cases, the first signal may be lethargy or a general sense that the animal is not thriving. The underlying cause varies. It may involve inflammation of the bowel wall, abnormal widening of the lymphatic vessels that drain the intestine, or another process that disrupts the gut's barrier. This page explores what protein-losing enteropathy looks like in practice, the mechanisms that can drive it, how it is investigated through blood tests and imaging, and the dietary and medical approaches used to manage it. The goal is to help you understand what may be happening and what shape the conversation with your vet may take.
Pulmonary Hypertension
Pulmonary hypertension describes sustained elevation of blood pressure within the vessels that carry blood from the heart to the lungs. This increased resistance can develop when underlying disease narrows or stiffens those vessels, or when the heart's left side struggles to receive blood efficiently, causing pressure to build backwards through the lungs. Owners often arrive at this topic after their dog has shown reduced tolerance for activity, episodes of breathlessness, or fainting, particularly during excitement or exertion. Cats may become quieter, breathe more rapidly at rest, or show reluctance to move. In many cases, pulmonary hypertension is discovered during investigation of a heart murmur, chronic cough, or known lung condition. It is rarely a disease in isolation: it tends to arise secondary to problems elsewhere in the heart or lungs. This page explores the signs an owner may observe, the mechanisms that raise pressure in the pulmonary circulation, the diagnostic steps used to estimate how likely it is and how severe it may be, and the range of approaches used to address both the elevated pressure and the conditions that drive it.
Pulmonary Thromboembolism
Pulmonary thromboembolism describes a situation in which a clot blocks one or more of the arteries that carry blood through lung tissue, either after travelling there from elsewhere in the body or after forming in the lung vessels themselves. When this happens, parts of the lung may not receive the blood flow they need to function, and the heart may need to work harder to push blood through the remaining open vessels. Owners often arrive at this page because their dog or cat has developed sudden difficulty breathing, seems unable to settle, or is breathing rapidly even at rest. In some cases, the animal may have a known condition elsewhere in the body, such as a heart problem, a hormonal disorder, or an immune condition, that has been mentioned as carrying this risk. The signs can appear without warning and may vary depending on how much of the lung's blood supply has been affected. This page explores what patterns tend to raise concern, what may be happening in the circulation and lung tissue, how the picture is investigated when this process is suspected, and what approaches exist once the condition is identified.
Pyelonephritis
Pyelonephritis is an infection that reaches the kidneys themselves, rather than remaining in the bladder or lower urinary tract. It tends to occur when bacteria travel upward through the ureters, or occasionally when infection spreads through the bloodstream. The kidney tissue becomes inflamed, and in some cases small abscesses can form. Owners often notice signs that overlap with simpler bladder infections (frequent urination, straining, or blood in the urine), but the animal may also seem generally unwell, with reduced appetite, lethargy, or visible discomfort in the back or flanks. Fever can be present, though not always. Some dogs and cats show very few outward signs early on, and the condition is identified during investigation of subtle or recurring urinary signs. This page explores the signals that may point towards kidney involvement, what happens in the tissue during infection, how pyelonephritis is investigated through imaging and laboratory work, and the range of approaches used to address it. The condition ranges from vague, low-grade illness to severe and rapid kidney injury, and the course it takes depends on factors including how quickly it is identified, the type of bacteria involved, and the overall health of the kidneys.
Pyothorax
Pyothorax is the accumulation of infected fluid, or pus, in the pleural space, the narrow compartment that surrounds the lungs inside the chest. This infection disrupts normal breathing mechanics and can make an animal feel profoundly unwell. It occurs in both cats and dogs, though the routes by which bacteria reach the pleural space often differ between species. Owners may notice laboured or rapid breathing, lethargy, reduced appetite, or a reluctance to move. Some animals run a fever; others may appear quiet and withdrawn rather than visibly distressed. The signs can develop over days or occasionally longer, and the severity an owner observes does not always map neatly to the extent of fluid or infection inside the chest. This page explores what pyothorax can look like from the outside, the mechanisms by which infection reaches the pleural space, how the condition is investigated through imaging and fluid analysis, and the approaches used to manage it, including drainage, antimicrobial therapy, and the decisions that shape recovery.
Rectal Prolapse
Rectal prolapse describes a situation in which part of the rectum, either its lining alone or the full thickness of its wall, protrudes through the anus, appearing as a visible, often cylindrical or rounded mass of pink or red tissue. It can occur as an isolated event or develop gradually, and tends to be associated with conditions that cause repeated straining, such as ongoing diarrhoea, constipation, or certain urinary or reproductive problems. Owners most often notice a fleshy tissue emerging from the back passage, which may appear after defaecation or straining, and in some cases may retract on its own or remain visible. The tissue can become swollen, darker in colour, or dry if it stays outside for a period of time. Young animals and those with chronic bowel issues are more commonly affected, though it can appear at any age. This page explores what owners may observe at home, what processes underneath tend to contribute to prolapse, how the condition is assessed, and what approaches exist for managing both the prolapse itself and any underlying cause.
Restrictive Cardiomyopathy in Cats
Restrictive cardiomyopathy describes a pattern in which the muscular walls of the heart become stiff and less able to relax properly between beats. This stiffness limits how much blood the chambers can accept, which in turn affects how efficiently the heart fills and pumps. In cats, this is a less common form of heart muscle disease than hypertrophic cardiomyopathy, and it leads to the same complications: fluid build-up from congestive heart failure and blood clots. Owners often arrive at this page after learning their cat has a heart murmur at a routine visit, or because their cat has become quieter, is breathing more rapidly, or has suddenly lost use of a hind leg. Some cats show no outward signs for months or years. The condition can also be identified during investigation of fluid accumulation in the chest or abdomen. This page explores the patterns that may prompt consideration of restrictive cardiomyopathy, what is understood about the changes in heart muscle that underlie it, how the condition is investigated using imaging and other tools, and the range of approaches used to support cats living with it.
Salivary Mucocele
A salivary mucocele forms when saliva leaks from a damaged salivary gland or duct and collects in the surrounding tissue, creating a fluid-filled swelling. The body walls off this pooled saliva with a soft tissue lining, forming what is sometimes called a pseudocyst. The swelling can appear in different places depending on which gland is affected. The most common sites are beneath the jaw or along the upper neck, and under the tongue. Less often it forms in the wall of the throat, where it can narrow the airway and cause breathing difficulty that can be fatal. Owners often notice a soft, fluctuant lump that may develop gradually or appear quite suddenly. The swelling itself is typically painless, though it can interfere with eating or swallowing if it becomes large or is positioned under the tongue. Some animals may drool more than usual, hold their head in an unusual position, or show difficulty closing the mouth comfortably. This page explores the signs that may prompt concern, what is happening beneath the surface to cause saliva to accumulate, how the condition is investigated and confirmed, and the range of approaches used to address it. The underlying cause of the initial leakage is often not identified, even after investigation.
Sick Sinus Syndrome
Sick sinus syndrome describes a pattern in which the heart's natural pacemaker (a small cluster of specialised cells in the right atrium called the sinus node) fails to generate electrical impulses consistently or at an appropriate rate. This can result in periods where the heart beats too slowly, pauses briefly, or alternates unpredictably between slow and fast rhythms. It is described mainly in middle-aged to older dogs. Owners often notice episodes of weakness, unsteadiness, or brief collapse, particularly during activity or excitement. Some animals appear quieter than usual, tire more easily on walks, or seem occasionally confused or distant. In many cases, these signs are intermittent and the animal appears entirely normal between episodes, which can make the pattern difficult to recognise at first. This page explores what sick sinus syndrome may look like in day-to-day life, the electrical and structural changes that underlie it, how the rhythm disturbance is identified and characterised, and the range of approaches used to manage it, from observation where there are no signs to medication or pacemaker implantation where there are.
Small Intestinal Bacterial Overgrowth
Small intestinal bacterial overgrowth describes a situation in which the population of bacteria in the small intestine becomes unusually large. The small intestine normally holds relatively few bacteria compared to the large bowel, and when that balance shifts, digestion and nutrient absorption can be disrupted. The result is often chronic diarrhoea, sometimes with weight loss, changes in appetite, or intermittent vomiting. Because a true increase in bacterial numbers is not always found, many vets now use terms such as antibiotic-responsive enteropathy or small intestinal dysbiosis for the same pattern. The condition can emerge at any age and for different reasons. In some dogs, particularly younger large-breed dogs such as German Shepherds, bacterial overgrowth appears without an obvious underlying cause. A relative deficiency of an antibody called IgA, which helps keep the intestinal environment in check, has been proposed as the reason in German Shepherds, but studies have given conflicting results and the link is not proven. In other cases, bacterial overgrowth develops secondary to another condition, such as exocrine pancreatic insufficiency or a problem with intestinal movement, and this secondary form can occur at any age, including in older dogs. This page explores what an owner may observe, what processes underneath may be contributing, how the condition is investigated, and what approaches exist to address it.
Snake Envenomation (Adder Bite)
Snake envenomation in the UK typically involves the adder (Vipera berus), Britain's only native venomous snake. When a dog or cat is bitten, venom is injected under the skin, triggering a cascade of local and sometimes systemic effects. The severity can range from mild swelling at the bite site to more widespread reactions affecting circulation, clotting, or other organ systems. Owners often notice sudden pain or distress during a walk in heath, moorland, or woodland, followed by swelling that may appear within minutes to hours. The bite site itself can be difficult to see beneath fur, and the degree of swelling or bruising varies. Some animals show only local signs, while others develop vomiting, lethargy, difficulty breathing from swelling around the throat, or collapse, sometimes several hours after seeming only mildly affected. Most dogs recover with treatment, though a small proportion die. This page explores the signals that may prompt concern, the mechanisms by which adder venom affects the body, the investigations used to assess severity and guide decisions, and the range of approaches taken in different cases. Each animal's response to envenomation is individual, shaped by factors including the volume of venom delivered, the site of the bite, and the animal's size and health.
Steroid Hepatopathy
Steroid hepatopathy describes a pattern of change in the liver that occurs in response to raised levels of corticosteroid hormones, either from the body's own overproduction (Cushing's disease) or from medication given for another condition. The liver cells accumulate glycogen, a storage form of glucose, which causes the liver to enlarge and alters the way it functions. Owners often notice increased drinking and urination, sometimes a pot-bellied appearance, or changes in appetite and energy. Blood tests taken for other reasons may show elevated liver enzymes, prompting questions about what is happening and whether the liver is being damaged. Raised liver enzymes can appear within days of starting corticosteroid medication, while outward signs tend to develop gradually and can be subtle at first. This page explores what steroid hepatopathy looks like from the outside, what is taking place inside the liver, how the underlying cause is identified, and the range of approaches used depending on whether the source of the corticosteroids is internal or external.
Tetralogy of Fallot
Tetralogy of Fallot is a structural condition of the heart that is present from birth, involving four connected abnormalities that together affect how blood flows through the heart and out to the body. The core issue is that oxygen-poor blood may bypass the lungs and mix with oxygen-rich blood, meaning the body receives less oxygen than it would in a normally formed heart. Owners most often notice this condition in young animals, particularly puppies and kittens, who may tire more easily during play, breathe more rapidly at rest, or appear less vigorous than their littermates. In some cases, the mucous membranes (gums, tongue) can take on a bluish tint, particularly after exertion. The severity can vary; some animals show signs early in life, whilst others may cope reasonably well for a period before limitations become apparent. This page explores the patterns that can appear, what is happening structurally inside the heart, how the condition is investigated through examination and imaging, and the range of approaches that exist for managing it. Each animal presents differently, and the course depends on the degree of abnormality and how the body adapts over time.
Third-Degree Atrioventricular Block
Third-degree atrioventricular block is a condition in which the electrical signals that normally coordinate the heartbeat between the upper chambers (atria) and lower chambers (ventricles) are completely interrupted. The heart continues to beat, but the upper and lower chambers contract independently of one another, often resulting in a slow and inefficient rhythm. This form of heart block represents the most complete disruption of the heart's internal conduction system. In dogs it carries a recognised risk of sudden death, whether or not outward signs are present. Cats are often less severely affected. Owners may notice episodes of weakness, collapse, or reduced exercise tolerance, though some animals show surprisingly few outward signs until the heart rate drops significantly. Because the ventricles generate their own rhythm when signals from above are blocked, the heart rate can vary depending on where that backup rhythm originates and how reliably it fires. The pattern can be persistent or intermittent, and the severity of signs often relates to how slow the heart becomes and whether the backup rhythm is stable. This page explores the signals that may accompany third-degree heart block, the underlying mechanisms that lead to complete conduction failure, the investigations used to confirm the diagnosis and assess the heart's function, and the range of approaches (including monitoring, medication, and pacing) that may be considered depending on the individual animal's circumstances.
Tricuspid Valve Dysplasia
Tricuspid valve dysplasia is a structural abnormality of the valve that sits between the right upper and lower chambers of the heart. The valve may be malformed in various ways: leaflets that are too thick, too thin, or attached unusually. This means it cannot close properly. When blood flows backward through the leaky valve, the right side of the heart works harder and may enlarge over time. Owners often arrive at this page because a heart murmur has been heard during a routine examination, or because a young dog is showing signs such as tiring easily, breathing more rapidly than expected, or developing a swollen abdomen. In some animals the condition causes no noticeable signs for months or years; in others, signs appear early in life. The pattern and timing vary widely between individuals. This page explores the signs that may be observed, what is happening inside the heart, how the condition is investigated through imaging and other tests, and the range of approaches used to support affected animals over time.
Ureteral Obstruction in Cats
Ureteral obstruction occurs when one or both of the narrow tubes that carry urine from the kidneys to the bladder become blocked. In cats, this is most often caused by small stones that form in the kidney and become lodged as they travel down the ureter, though scar tissue, blood clots, or less commonly tumours can also create a blockage. The obstruction prevents urine from draining normally, and pressure builds back up into the affected kidney, which can lose function permanently if the blockage is not relieved. Owners often notice reduced appetite, quiet behaviour, or vomiting that may seem vague at first. Some cats show discomfort in the abdomen or back, though this is not always obvious. The condition tends to develop over hours to days, and the signs can be subtle until the obstruction has been present for some time. It is diagnosed most often in middle-aged cats, and some individuals form stones more readily than others. This page explores the patterns that may prompt investigation, what is happening inside the urinary tract when flow is interrupted, the imaging and tests used to identify and locate an obstruction, and the range of approaches, from medical management to surgical procedures, that exist depending on the nature and duration of the blockage.
Ureteroliths
Ureteroliths are stones lodged within the ureters, the narrow tubes that carry urine from each kidney down to the bladder. These stones form in the kidney when minerals in the urine crystallise and aggregate, most commonly calcium oxalate, and after moving into the ureter they may lodge at any point along its length. When a stone obstructs the flow of urine from a kidney, that kidney cannot drain, and pressure builds. Many animals with ureteroliths show no outward signs until a stone causes partial or complete obstruction. At that point, an owner may notice reduced appetite, quietness, vomiting, or weight loss, though the picture varies and none of these signs is specific to a ureteral stone. Some stones are discovered incidentally during imaging for another reason. The condition occurs in both dogs and cats, with calcium oxalate ureteroliths seen more often in certain breeds, including miniature schnauzers and Yorkshire terriers in dogs, and Burmese, Persian, and Ragdoll cats. This page explores the signals an owner may observe, the mechanisms that lead to stone formation and obstruction, the imaging and laboratory work used to locate and characterise ureteroliths, and the range of approaches available when a stone is confirmed, from monitoring and dietary influence through to procedures that remove or bypass the stone.
Urinary Stones (Urolithiasis)
Urinary stones are mineral crystals that form inside the bladder or, less commonly, in the kidneys or the tubes connecting them. They vary in size from sand-like grains to pebbles, and their composition differs: some are made of struvite, others of calcium oxalate, urate, or rarer minerals. The type of stone influences how it behaves and what may help manage it. Many owners notice straining to urinate, frequent small puddles, blood in the urine, or signs of discomfort when their dog or cat tries to pass water. In male cats and small male dogs, a stone can lodge in the urethra and obstruct the flow of urine entirely, which tends to show as repeated straining that produces little or no urine. A complete blockage is life-threatening and, in cats, can be fatal within 2 to 3 days without treatment. Some animals carry stones without obvious signs, and the stones are found during imaging for another reason. This page explores what urinary stones can look like in daily life, what drives their formation, how they are identified through urine tests and imaging, and the range of approaches, from dietary adjustment to surgical removal, that may be considered depending on the stone type, size, location, and the animal's broader picture.
Uterine Inertia
Uterine inertia refers to a situation in which the muscular contractions of the uterus during labour become weak, infrequent, or stop altogether, preventing the normal progression of birth. It is the most common cause of difficult birth (dystocia) in dogs, and the puppies or kittens still inside can die while labour is stalled, so the timescales that matter are minutes and hours. This can occur at the start of labour (primary inertia) or after one or more puppies or kittens have been delivered (secondary inertia). The underlying causes vary and may include exhaustion of the uterine muscle, low calcium or glucose levels, mechanical obstruction, or insufficient hormonal signals. Owners most often notice that labour has started but then stalls: contractions may seem absent or ineffective, and no puppy or kitten appears despite straining, or there may be long gaps between births with signs of maternal distress or exhaustion. In some cases, labour never begins at all despite the pregnancy reaching or passing the expected due date. This page explores the signals that may point towards uterine inertia, the metabolic and mechanical factors that can contribute, the investigations used to assess the situation, and the range of approaches that may be considered depending on the individual circumstances.
Vaginal Hyperplasia
Vaginal hyperplasia is a swelling of the tissue lining the vagina, triggered by the hormonal changes that occur during a female dog's oestrous cycle. The tissue becomes engorged and oedematous, and in some cases a portion of it may protrude visibly from the vulva. This tends to be seen in younger intact female dogs, often during one of their first few heats, and the appearance can be concerning for owners who notice a rounded, glistening mass that was not present before. The degree of swelling varies. Some dogs show only mild internal changes that cause no outward signs, while others develop significant protrusion that may be accompanied by licking, difficulty urinating, or occasional bleeding. The condition typically resolves on its own as hormone levels shift through and beyond the heat cycle, though recurrence with future cycles is common. This page explores the patterns that may be observed, the hormonal mechanism underlying the tissue change, the ways it can be assessed, and the range of approaches, from monitoring through a cycle to surgical options for dogs with recurrent or complicated cases.
Ventricular Septal Defect
A ventricular septal defect is an opening in the wall that normally separates the left and right pumping chambers of the heart. Blood flows through this opening in a direction and volume determined by the size of the defect and the pressure difference between the two sides, often creating a heart murmur that can be detected during routine examination. Many animals with small defects show no outward signs and live ordinary lives, while larger defects can lead to exercise intolerance, slower growth, or breathing changes as the heart and lungs work harder to compensate. Owners often arrive on this page after a murmur has been heard during a puppy or kitten check, or when an older animal begins to tire more easily than expected. This page explores what can be observed at home and during examination, what is happening inside the heart and circulation, how the defect is measured and characterised, and the range of approaches (from monitoring alone to surgical repair) that may be considered depending on the individual animal and the size of the opening.
Xylitol Toxicity in Dogs
Xylitol is a sugar substitute found in many household products, including sugar-free gum, certain peanut butters, baked goods, some medications, and dental products. In dogs, even small amounts can trigger a rapid release of insulin, causing blood glucose to drop to dangerously low levels; in some cases, it can also cause severe liver injury. Cats do not appear to be affected in the same way, and the focus here is on dogs, where toxicity is well documented. Owners often arrive on this page after a dog has eaten something containing xylitol, or after noticing signs such as weakness, wobbliness, vomiting, or collapse. Hypoglycaemia may develop within thirty to sixty minutes of ingestion, though with products that slow absorption, including certain chewing gums, signs can be delayed for up to twelve to eighteen hours. Outward signs of liver injury, when it occurs, tend to appear twenty-four to forty-eight hours or more after ingestion. This page explores what xylitol toxicity can look like, what is happening inside the body, how veterinary teams investigate and monitor affected dogs, and the range of approaches used to manage hypoglycaemia and support liver function when needed.
Immune & Inflammatory Health
Acute Moist Dermatitis (Hot Spots)
Acute moist dermatitis describes areas of skin that become inflamed, moist, and raw very quickly, often within hours. These patches are sometimes called hot spots because they can feel warm to the touch and tend to appear suddenly, usually after scratching, licking, or rubbing at one area. The skin breaks down rapidly, producing a wet, matted surface that may smell unpleasant and can be painful. Owners often notice their dog is bothering a single spot obsessively, and by the time the fur is parted, the skin underneath is already red, weeping, and often larger than expected. This pattern is more common in dogs with thick or double coats, in warm weather, or after swimming or bathing. Cats can develop similar lesions, though this occurs less frequently. This page explores what signs may suggest acute moist dermatitis, what processes beneath the skin drive the rapid progression, how the condition is distinguished from other causes of inflamed skin, and what approaches exist to manage both the current lesion and any underlying trigger.
Acute Polyradiculoneuritis in Dogs
Acute polyradiculoneuritis is an inflammatory condition affecting the nerve roots where they emerge from the spinal cord. It causes a progressive weakness that tends to begin in the back legs and can spread forward to all four limbs within a few days, and in some dogs to the muscles of the face and voice. The inflammation is thought to be immune-mediated: the body's immune system responding to a trigger that is often not identified, though in some cases there may be a history of recent illness or a diet that included raw chicken. Owners often notice that their dog has become weak in the hindlimbs, with a shuffling or wobbly gait that worsens quickly. In many cases the weakness progresses to the point where the dog cannot stand or walk, though the tail may still wag and the dog remains alert. The underlying process is typically self-limiting: most dogs begin to improve spontaneously within three weeks, though full recovery can take several months and depends on supportive care during the weakest phase. The main danger comes in the first days while weakness is still spreading: in severe cases it reaches the breathing muscles, and death from breathing failure can occur without ventilator support. This page explores the patterns that may be observed, what is understood about the immune and nerve processes involved, the investigations used to clarify the picture, and the range of supportive and therapeutic approaches that exist.
Alabama Rot (CRGV)
Alabama rot, formally called cutaneous and renal glomerular vasculopathy (CRGV), is a condition in which small blood vessels in the skin and sometimes the kidneys become damaged and blocked by tiny clots. The cause remains unknown. It is rare: typically fewer than 50 confirmed cases are recorded each year in the UK, though the condition attracts significant attention because of its severity and the uncertainty surrounding it. Owners most often notice unexplained skin lesions, particularly on the legs or paws: areas that can appear red, ulcerated, or swollen without an obvious injury. In some dogs the kidneys are also affected, typically within days of the skin lesion. Most dogs that develop kidney injury do not survive, while dogs whose kidneys stay unaffected usually recover. The pattern and progression can vary, and the condition can resemble other causes of skin wounds or illness. This page explores what is observed in affected animals, what may be happening beneath the skin, how the condition is investigated, and the approaches that may be considered when CRGV is suspected. It also examines what is currently understood, and not yet understood, about how and why it occurs.
Alopecia X
Alopecia X is a non-inflammatory condition in which hair is gradually lost from the body, leaving darkly pigmented skin beneath. It occurs mainly in Nordic or Spitz-type breeds with thick, plush double coats, including Pomeranians, Chow Chows, Keeshonds, Samoyeds, and Alaskan Malamutes, with Pomeranians the most heavily represented of these. Miniature and Toy Poodles are also recognised as affected despite their different coat type. The condition typically begins in early adulthood. The guard hairs are lost first, often leaving a soft, puppy-like undercoat for a time, though this may also thin over months to years. The head and legs tend to remain unaffected. Owners often notice a symmetrical thinning or complete loss of coat on the trunk, neck, and hindquarters, with the skin becoming visibly darker in the bald areas. The condition does not cause discomfort, itching, or ill health; it is purely cosmetic. Hormonal diseases that do affect health, such as hypothyroidism and Cushing's disease, can produce a very similar pattern of hair loss and darkened skin, and the coat alone does not tell them apart. The underlying cause remains uncertain, and the condition has carried many names over the decades, including black skin disease, coat funk, and hair cycle arrest, reflecting this lack of clarity. This page explores what patterns of hair loss may signal the condition, what is understood about the biology of the hair follicle in affected dogs, how the condition is investigated and distinguished from other causes of hair loss, and what approaches exist for managing coat appearance when that matters to an owner.
Anal Sac Abscess
An anal sac abscess occurs when one of the small scent pouches located on either side of a dog's anus becomes infected and fills with pus. These pouches normally release a small amount of fluid during defaecation, but if the duct becomes blocked, bacteria can multiply inside the sac, leading to swelling, pain, and sometimes rupture through the skin. Owners often notice sudden swelling beside the anus, usually on one side only, or may observe their dog scooting, licking the area persistently, or showing discomfort when sitting or passing faeces. The swelling may feel firm and warm, and in some cases a tract opens and drains blood-tinged or foul-smelling material. The presentation can look alarming, particularly if there is visible discharge or an open wound. This page explores the signs that may be present, what is happening within the sac and surrounding tissue, how the condition is typically investigated, and the range of approaches used to address both the current abscess and, where relevant, reduce the chance of recurrence.
Anaphylaxis
Anaphylaxis is a body-wide, rapid-onset reaction that occurs when immune cells release large amounts of inflammatory substances in response to a trigger. The trigger is most often a substance the body has encountered before, but some reactions occur on a first exposure. The reaction involves multiple body systems at once, with the pattern of signs depending on which organs are most affected in that species. In dogs, this often appears as sudden vomiting, bloody diarrhoea, or collapse, because the liver and gut contain the highest concentration of reactive cells; in cats, difficulty breathing tends to be more prominent, as the lungs are the primary target. Owners often arrive at this page after observing sudden, unexpected signs that developed within minutes of an event: an injection, an insect sting, or occasionally a food. The severity can range from distressing to life-threatening, and the reaction can be fatal within minutes without treatment. The signs may involve breathing, circulation, the gut, or the skin in various combinations. The page that follows explores what anaphylaxis can look like when it first appears, what is happening beneath those signs, how the reaction is identified and distinguished from other causes, and what approaches exist for managing it and reducing the chance of recurrence.
Anaplasmosis
Anaplasmosis is an infection caused by bacteria transmitted through tick bites. The bacteria, most commonly Anaplasma phagocytophilum, invade a type of white blood cell called neutrophils, which can trigger signs of illness in some dogs, while others remain symptom-free despite testing positive. Owners may notice a period of lethargy, reduced appetite, or fever days to weeks after a tick has been found or suspected. In other cases, the infection is discovered incidentally during routine blood work in a dog who appears entirely well. Dogs with clinical signs typically respond within a day or two once antibiotic treatment begins, while those without symptoms may simply be monitored. This page explores what anaplasmosis can look like, how the infection develops, the ways it is identified through testing, and the approaches used when treatment is warranted.
Angioedema and Urticaria in Dogs
Angioedema and urticaria are visible reactions in the skin that happen when certain immune cells release chemicals, particularly histamine, in response to something the body has encountered. Urticaria appears as raised, often itchy welts or hives in the skin, while angioedema involves deeper swelling, typically around the face, muzzle, eyelids, or ears. Both can occur together or separately, and both tend to appear quite suddenly. Owners often notice facial swelling that develops over minutes to hours, sometimes with a puffy or distorted appearance around the eyes or lips. The swelling may be accompanied by patches of raised skin elsewhere on the body. Triggers can include insect stings, medications, vaccines, foods, or contact with plants or chemicals, though in many cases no specific cause is identified. The reaction may resolve on its own or may persist, and the degree of swelling varies. The same triggers can also cause anaphylaxis, a reaction affecting the whole body, which in dogs usually shows as sudden vomiting, diarrhoea, drooling, pale gums, weakness or collapse within minutes of exposure and can be fatal. This page explores the signals that may accompany these reactions, the immune mechanisms underlying them, how they are investigated when the cause is unclear, and the range of approaches used to manage symptoms and reduce recurrence.
Aspergillosis (Nasal)
Nasal aspergillosis is a fungal infection of the nasal passages and sinuses, most often caused by a species of mould called Aspergillus fumigatus. The fungus can colonise the lining of the nose, leading to inflammation, discharge, and sometimes destruction of the delicate structures inside. It occurs most commonly in dogs, particularly those with longer noses, and is rare in cats. Owners often notice a persistent nasal discharge, usually thick (mucus- or pus-like) and often streaked with blood, that may start on one side and later affect both nostrils. Sneezing, nosebleeds, or a change in the appearance of the nostril itself can also occur. The signs tend to develop gradually, and many dogs remain otherwise well in the early stages. This page explores what nasal aspergillosis may look like in practice, what is understood about how the infection takes hold, how it is investigated using imaging and sampling, and the range of approaches that exist for managing it. The goal is to help you understand what may be happening and what questions might be useful to consider.
Atopic Dermatitis in Dogs
A chronic inflammatory skin condition driven by immune hypersensitivity to environmental allergens, causing recurring itch and discomfort.
Balanoposthitis in Dogs
Balanoposthitis describes inflammation affecting the glans of the penis and the prepuce, the fold of skin that covers it. In dogs, this tends to present as discharge from the prepuce, often noticed as spotting on bedding or licking behaviour directed at the area. The discharge may be clear, cloudy, yellow, or green, and can vary in amount from occasional to persistent. Many healthy male dogs produce a small amount of preputial discharge as a normal finding, which can make it difficult for owners to know when something has shifted into a condition that warrants attention. Inflammation in this area can arise from infection, irritation, foreign material, trauma, or underlying anatomical factors, and the pattern of signs often helps narrow the picture. This page explores the signals that may accompany balanoposthitis, what is happening beneath the surface, how the condition is investigated, and the range of approaches used to address it.
Bartonellosis
Bartonellosis is an infection caused by bacteria of the Bartonella genus, which can affect dogs and cats in different ways. In cats, these bacteria are spread mainly by cat fleas and their droppings, and in dogs fleas and possibly ticks are thought to be involved. People are usually infected through a cat scratch. The bacteria can establish persistent infections that may affect the blood, immune system, heart valves, or other organs. In many cases, infected animals show no signs at all, though some develop fever, lethargy, inflammation in various parts of the body, or less common patterns involving the heart, eyes, or nervous system. Owners often arrive at this page after a positive test result in an animal that appears well, or after episodes of unexplained fever, lameness, or swelling that have been difficult to link to a clear cause. Because the signs can be subtle, intermittent, or absent, and because these bacteria are found in healthy animals as well as unwell ones, the question of what the test means for a particular pet is often central. This page explores what patterns of illness can be associated with Bartonella infection, how the bacteria interact with the body, how infection is detected and interpreted, and what approaches exist when treatment is considered. The aim is to help you understand what may be happening and what conversations may follow.
Bee and Wasp Stings
A bee or wasp sting is a localised injection of venom through the skin, triggering an immune response that produces swelling, redness, and discomfort at the site. Most stings in dogs and cats result in mild, self-limiting reactions confined to the area of the sting itself, often a paw, face, or mouth if the animal has snapped at or investigated the insect. In some animals, the immune system responds more extensively, producing swelling beyond the area around the sting or a systemic reaction affecting breathing, circulation, or other organ systems. Owners typically notice sudden pawing at the face, licking at a limb, visible swelling, or a clear point of pain that was not present moments before. The reaction may appear within minutes or develop more gradually over the first hour or two. Stings inside the mouth or throat, common when an animal catches or eats an insect, can produce swelling that is less visible from the outside but may affect breathing or swallowing. This page explores what signals suggest a sting has occurred, the mechanisms underlying local and systemic reactions, how the severity and type of response are assessed, and the range of approaches used to manage reactions of differing intensity and distribution.
Bite Wound Infection
A bite wound infection develops when bacteria introduced during a bite, from another animal or occasionally a human, multiply in the damaged tissue. Dogs and cats both give and receive bites, and the mouth of any animal carries a complex population of bacteria. Even a puncture that looks small on the surface can seed infection deep in the tissue, particularly when teeth create narrow, oxygen-poor channels that certain bacteria favour. Owners often notice swelling, heat, or discharge appearing a day or more after the original incident, sometimes after the initial wound seemed minor or had been overlooked. The site may become painful, and the animal may be reluctant to use the affected area or allow it to be touched. In some cases the wound breaks open and drains, while in others the infection remains enclosed and continues to expand beneath the skin. This page explores the signals that may suggest infection is developing, what happens in the tissue when bacteria take hold, how the extent and nature of infection can be assessed, and the range of approaches used to resolve it. The goal is to help you understand what you may be observing and the shape of the conversations and decisions that may follow.
Blepharitis in Dogs
Blepharitis is inflammation of the eyelids. It can affect one or both eyes, and may involve the skin, the eyelid margins, or the glands and follicles within the lid itself. The inflammation can arise from infection, allergy, immune activity, anatomical factors, or conditions affecting the skin more broadly. Owners often notice redness, swelling, discharge, crusting along the lash line, or signs that the eye area is uncomfortable: rubbing, mild squinting, or increased tearing. The eyelids may appear thickened or the hair around them may be lost. In some cases blepharitis occurs alongside other skin or eye conditions, and in others it appears on its own. This page explores the signals that may accompany eyelid inflammation, the mechanisms and causes that can drive it, how it is investigated, and the range of approaches used to manage it.
Blood Transfusion Reaction
A blood transfusion reaction is an unwanted effect of receiving donated blood. Most are caused by the immune system responding to the donated blood, though some, such as fluid overload in the lungs, are not. Most animals receiving a transfusion tolerate it well, and where a reaction does occur, a mild and self-limiting rise in temperature is the most commonly reported pattern; reactions can nonetheless range from mild and transient to severe and life-threatening. These reactions may begin during the transfusion itself or appear hours to days afterwards. Owners may notice sudden restlessness, changes in breathing, vomiting, or collapse during or shortly after a transfusion, though many reactions produce subtler signs such as fever, dark urine, or a temporary worsening of weakness. The pattern and timing of signs can offer clues about the type of reaction involved. This page explores the signals that may suggest a transfusion reaction, the immune and physiological mechanisms that underlie different reaction types, the investigations used to identify and characterise a reaction, and the approaches available for management and prevention in animals who may need future transfusions.
Bordetella in Cats
Bordetella is a bacterial infection of the airways caused by *Bordetella bronchiseptica*. The bacteria settle in the trachea and bronchi, triggering inflammation that leads to the respiratory signs an owner may observe. It is one of several infectious organisms that can contribute to upper respiratory disease in cats, particularly in environments where multiple cats live together. An owner most commonly notices sneezing, a harsh cough, nasal discharge, or noisy breathing. The signs often develop within a few days of exposure and typically last 7 to 10 days in otherwise healthy cats, though younger or stressed cats may experience more severe or prolonged illness. Some cats remain well but carry and shed the bacteria for several months after exposure, which means they can pass the infection to other cats even when they appear healthy. This page explores the signs that may prompt concern, what is happening in the airways during infection, how the condition is investigated, and the range of approaches that exist for managing it.
Brucella canis
*Brucella canis* is a bacterial infection that spreads between dogs and can affect several body systems, though it is often recognised first through problems with breeding: late pregnancy loss, weak or stillborn puppies, or difficulty conceiving. In the UK, cases have been uncommon historically, but numbers have risen since 2020, largely in dogs imported from overseas, and transmission between dogs living in the UK has now been documented. Many infected dogs, possibly most, carry the infection without outward signs, whilst others may develop back pain, lameness, lethargy, or swelling around the reproductive organs. *Brucella canis* is zoonotic, meaning it can pass from dogs to people, and a confirmed dog-to-human case has been documented in the UK. Detection of the infection in a dog is reportable to the Animal and Plant Health Agency (APHA) in England, Scotland and Wales, and notifiable to the Department of Agriculture, Environment and Rural Affairs (DAERA) in Northern Ireland. This page explores what patterns of change or difficulty might raise the possibility of *Brucella canis*, what is happening in the body during infection, how the diagnosis is investigated through blood tests and other means, and what approaches exist for managing the condition in individual dogs and reducing spread to other dogs and to people within households or breeding environments.
Brucellosis in Dogs
Brucellosis in dogs is a bacterial infection caused by Brucella canis, an organism that tends to settle in the reproductive organs and lymph nodes. The infection spreads between dogs through mating, contact with birth or abortion material and other body fluids such as urine, from a mother to her puppies in the womb or through milk, and through contaminated environments. It can persist for months or years without obvious signs, and dogs with no signs can still be infectious. Brucella canis can also infect people, mainly through contact with birth or abortion material and other body fluids from an infected dog; young children and people who are immunosuppressed may be at higher risk of severe illness. In England, Scotland and Wales, a positive test result in a dog is reportable to the Animal and Plant Health Agency (APHA) by the vet and the laboratory. In Northern Ireland it is notifiable to DAERA. Owners often encounter this condition in one of several ways: difficulty achieving pregnancy despite repeated breeding attempts, unexpected loss of a litter in mid- to late pregnancy, or discharge from the reproductive tract that prompts investigation. In other cases, the infection is identified through testing of dogs imported or rescued from abroad, or through screening before breeding. Some dogs may show signs such as lethargy, enlarged lymph nodes, lameness or back pain, though many appear entirely well. This page explores the signals that may prompt investigation, the mechanisms by which the infection affects the body, the tests used to identify and monitor it, and the approaches taken to manage it in affected dogs and breeding populations.
Calcinosis Cutis
Calcinosis cutis describes a process in which calcium salts are deposited in the skin, forming firm nodules, plaques, or crusty patches that can appear across different parts of the body. These deposits develop when the normal balance that keeps calcium in solution is disrupted, most often as a complication of other conditions rather than appearing on their own. Owners typically notice raised, hard lumps or gritty areas under the skin that may feel like small stones, sometimes with chalky material visible at the surface or seeping from the skin. The areas can be uncomfortable, and the overlying skin may become inflamed, ulcerated, or prone to infection. In dogs, this pattern is most commonly seen in animals with hormonal imbalances, particularly those affecting the adrenal glands, though other triggers exist. This page explores the signs that may raise suspicion, the mechanisms that lead to calcium deposition in different scenarios, the investigations that help clarify what is driving the process, and the range of approaches used to manage both the deposits and the underlying causes.
Campylobacteriosis
Campylobacteriosis is an infection of the digestive tract caused by bacteria in the Campylobacter genus. These bacteria can settle in the intestines and cause inflammation, leading to diarrhoea that may contain mucus or blood. Many dogs and cats carry Campylobacter without showing any signs, but younger animals, those with other health conditions, or those under stress may develop symptoms. Owners most often notice loose or watery stools that appear suddenly, sometimes with a distinctly foul smell or visible streaks of blood. The diarrhoea may be accompanied by a reduced appetite, occasional vomiting, or signs of mild abdominal discomfort. In many adult animals, signs resolve on their own within about a week, although some animals have intermittent diarrhoea for longer. The bacteria may persist in the gut for weeks or months. In young puppies and kittens, bloody diarrhoea with vomiting or dullness overlaps with more serious infections such as parvovirus, and small animals can become dehydrated within a day or two. Campylobacter is also a zoonosis. Campylobacter jejuni and Campylobacter upsaliensis carried by dogs and cats can infect people by the faecal-oral route, when hands become contaminated from faeces, bedding or the coat of an affected animal. Between 2016 and 2018 an outbreak in the United States linked more than a hundred human infections to contact with puppies. People with a weakened immune system, young children and older people tend to be more vulnerable to severe illness. This page explores what patterns tend to raise suspicion for campylobacteriosis, what happens in the intestinal lining during infection, how the condition is investigated through faecal testing, and what approaches exist for managing symptoms and supporting recovery.
Canine Acne
Canine acne is a skin condition affecting the chin and muzzle, where hair follicles become blocked and inflamed. It appears most often in young dogs during adolescence, though it can occur at any age. The blocked follicles may look like small bumps, blackheads, or areas of redness, and in some cases the skin can develop pustules or become thickened and swollen. Owners often notice it when grooming or handling their dog's face, or when the chin appears persistently dirty despite cleaning. Short-coated breeds are affected more often, including flat-faced breeds such as Boxers and Bulldogs. Mild cases may come and go without treatment, while others persist or worsen over time. This page explores what canine acne can look like in practice, what is happening in the skin to produce these changes, how the condition is investigated and distinguished from other causes of facial inflammation, and the range of approaches used to manage it.
Canine Parvovirus
Canine parvovirus is a viral infection that spreads quickly between dogs and targets rapidly dividing cells, particularly those lining the intestines and, in very young puppies, rarely the heart muscle. The virus causes severe damage to the gut lining, which leads to profuse, often bloody diarrhoea, vomiting, and rapid deterioration. It tends to affect unvaccinated puppies and young dogs most severely, though dogs of any age without immunity can become unwell. Owners often arrive at this page because their dog has developed sudden, watery or bloody diarrhoea alongside vomiting, lethargy, and loss of appetite, sometimes within a day or two of seeming entirely well. The illness can progress quickly, and the distinctive smell and appearance of the diarrhoea may prompt concern about parvovirus specifically. Some will be weighing up early signs in a new puppy, while others may be trying to understand a diagnosis that has just been made. This page explores what canine parvovirus looks like in practice, what happens inside the body during infection, how the condition is identified, and the range of approaches used to support affected dogs through the illness. It also considers prevention, prognosis, and the factors that influence outcome.
Canine Viral Papillomatosis (Warts)
Canine viral papillomatosis is a condition in which small, rough growths appear on a dog's skin or mucous membranes, most often around the mouth, lips, and muzzle. These growths, commonly called warts, are caused by infection with canine papillomavirus and tend to occur in younger dogs, typically under two years of age, though older dogs with weakened immune systems can also be affected. The growths often appear suddenly and can vary from a single small bump to clusters that may look cauliflower-like in texture. Many owners notice the growths during play, grooming, or feeding, and wonder whether they are painful, contagious, or require treatment. In most cases, the warts cause little discomfort and resolve on their own as the dog's immune system clears the virus, though this can take several weeks to months. Occasionally, growths may bleed if traumatised, or interfere with eating or swallowing if they are large or numerous. This page explores what these growths may look like and where they tend to appear, what is happening beneath the surface as the virus interacts with the immune system, how the condition is investigated and confirmed, and what approaches exist when observation alone is not suitable.
Carnassial Tooth Abscess in Dogs
A carnassial tooth abscess is a bacterial infection that forms at the root of one of the large chewing teeth in the upper jaw, specifically the fourth premolar, which is part of the carnassial tooth pair in dogs. These teeth sit high in the jaw, with roots that extend upward into the bone just below the eye. When infection develops, it often tracks through the bone and appears as swelling on the face. Many owners first notice a lump or soft swelling below the eye, sometimes on one side of the muzzle. The area may feel warm, and in some cases a small opening develops in the skin that drains intermittently. The dog may eat more slowly, favour one side when chewing, or show no obvious discomfort at all. Pain signals can be subtle, and some dogs continue eating normally even when infection is present. This page explores what signs can appear and when, what is happening beneath the surface of the gum and bone, how the infection is investigated and confirmed, and what approaches exist for managing it. The goal is to help you understand what you may be observing and what shape the conversations ahead might take.
Cat Bite Abscess
A cat bite abscess forms when bacteria from a bite wound track beneath the skin, triggering an infection that becomes walled off by the body's immune response. The result is a pocket of pus that may develop over days following a bite, often from another cat. The original puncture wound can be tiny and easy to miss, but the abscess that follows may become quite obvious. Owners often notice a soft, warm swelling under the fur, sometimes accompanied by lethargy, reduced appetite, or a fever. The area may be painful to touch, and in some cases the abscess ruptures on its own, releasing thick, often foul-smelling discharge. Bite wounds around the head, neck, limbs, and base of the tail are common sites, reflecting typical patterns of cat-to-cat conflict. This page explores what signs may appear at different stages, what is happening beneath the skin as the infection develops, how the condition is investigated, and what approaches exist for managing both the abscess and the underlying wound.
Cheyletiellosis
Cheyletiellosis is a skin condition caused by surface-dwelling mites that live in the outer layers of the coat and skin. These mites produce visible flaking that often moves when the coat is parted, sometimes described as "walking dandruff", and can cause itching, though not every animal shows obvious discomfort. The condition can affect dogs, cats, and rabbits, and the mites can temporarily cause irritation in people who handle affected animals. Owners often notice excessive flaking along the back, a change in coat texture, or scratching that seems out of proportion to what they can see. Young animals and those in multi-pet households or from certain environments tend to be encountered more often, though any animal can be affected. The degree of itching varies widely; some animals show intense discomfort, while others appear relatively unbothered despite visible flaking. This page explores the signals that may prompt consideration of cheyletiellosis, what is happening on and within the skin, how the condition is investigated, and the range of approaches used to address it.
Chlamydophila Conjunctivitis in Cats
Chlamydophila conjunctivitis in cats is an infection of the tissues around the eye caused by the bacterium *Chlamydia felis*. The infection leads to inflammation of the conjunctiva, the thin membrane lining the eyelids and covering the white of the eye, and typically produces redness, swelling, and discharge that may start clear and later become thicker or coloured. The infection often begins in one eye but tends to become bilateral within a day or two. Owners may notice squinting, a red or swollen appearance around one or both eyes, or discharge that prompts wiping or cleaning. Young cats are most commonly affected, and signs tend to be most pronounced around nine to thirteen days after onset, then gradually ease over the following weeks, though the conjunctivitis can persist if untreated. The condition is distinct from other common causes of feline conjunctivitis, such as herpesvirus or calicivirus. This page explores the signals that may appear, what is happening beneath the surface, how the infection is investigated, and the approaches that exist for managing it.
Chronic Bronchitis in Dogs
Chronic bronchitis in dogs describes persistent inflammation of the airways in the lungs, the branching tubes that carry air down towards the smaller air sacs. This inflammation thickens the airway walls, prompts mucus production, and narrows the space through which air moves, making breathing less efficient over time. Owners most often notice a hacking cough that has been present for weeks or months, typically worse after excitement, exercise, or when the dog pulls on the lead. The cough may sound harsh and dry, or moist when there is more mucus in the airways, and often ends with a retch or gag as mucus is brought up, which can be mistaken for vomiting or for trying to clear something from the throat. Many dogs remain otherwise bright and active, especially early on, which can make the persistence of the cough puzzling. This page explores the signals that may point towards airway inflammation, what happens in the lungs when chronic bronchitis develops, how the condition is investigated and distinguished from other causes of long-term cough, and the range of approaches used to manage airway inflammation and support comfortable breathing.
Chronic Upper Respiratory Disease in Cats
Chronic upper respiratory disease in cats describes a pattern in which signs affecting the nose, throat, and airways persist or recur over weeks to months, rather than resolving within the usual timeframe of an acute infection. Owners often notice ongoing sneezing, nasal discharge, noisy breathing, or intermittent flare-ups that seem to settle and then return. The underlying picture can involve lingering viral activity, secondary bacterial involvement, structural changes to the delicate tissues of the nasal passages, or a combination of these. Cats with this pattern may have a history of early or severe respiratory infection (often as kittens) or may have developed symptoms more gradually over time. The day-to-day experience varies widely: some cats live comfortably with mild, occasional signs, while others experience more persistent disruption to breathing, appetite, or quality of life. This page explores what owners may observe, the biological and infectious processes that can sustain these signs, the ways the condition is investigated, and the range of approaches used to manage symptoms and support long-term comfort.
Colour Dilution Alopecia
Colour dilution alopecia is a pattern of hair loss that can occur in dogs whose coat colour comes from a diluted version of a standard pigment: blue (dilute black), fawn (dilute red), or silver tones. The hair itself tends to be more fragile than usual, and over time it may break, thin, or fall out, typically starting in the first few years of life. The skin underneath may look dry, flaky, or prone to minor infections. Owners often notice patchy thinning, a dull or moth-eaten appearance to the coat, or that their dog's coat never seems to grow back properly after clipping. The pattern usually develops gradually, and while the appearance can be concerning, the condition itself does not cause pain or systemic illness. This page walks through the signs that may be observed, what is understood about the underlying fragility of dilute-pigmented hair, how the pattern is investigated and distinguished from other causes of hair loss, and what approaches exist to support skin and coat health over time.
Cryptococcosis
Cryptococcosis is an infection caused by a fungus called Cryptococcus, which lives in the environment and can sometimes establish itself in a dog or cat's body. The fungus is typically inhaled, and while many animals may encounter it without consequence, in some cases it can lead to signs of illness, particularly affecting the respiratory system, nervous system, or other areas. Cats appear to develop this infection more often than dogs, and it tends to occur when something about an individual animal's circumstances allows the fungus to take hold. Owners often notice signs that can be quite varied depending on where the infection has established: sneezing, nasal discharge, firm swellings on the face or nose, changes in behaviour or coordination, skin lumps, or signs related to the eyes. Because the presentation can differ considerably from one animal to another, and because these signs can overlap with many other conditions, the path to recognising cryptococcosis often involves a period of investigation. This page explores the signals that can raise the possibility of cryptococcosis, the biological events that allow the fungus to cause illness, the tests used to identify it, and the approaches available for managing it. The information here is intended to help you understand the condition in context, not to determine whether your own animal is affected.
Cryptosporidiosis
Cryptosporidiosis is an infection of the intestinal lining caused by Cryptosporidium, a microscopic parasite that lives inside the cells of the gut wall. In dogs and cats, it often causes watery diarrhoea, though many infected animals show no signs at all, particularly if their immune system is working well. Owners typically encounter this condition when a young animal, a recently adopted pet, or one with another health condition develops persistent loose stools that may not respond quickly to initial supportive care. The diarrhoea can be intermittent, and the animal may otherwise seem reasonably bright. Some Cryptosporidium species are a recognised risk to people, particularly young children and those with weakened immune systems, so questions about household transmission often accompany questions about the pet's own health. The species usually found in dogs and cats infect people only rarely, and much less often than the species people catch from each other or from farm animals. This page explores what cryptosporidiosis can look like in the animal, what may be happening in the gut, how the infection is identified, and the range of approaches used when treatment is considered. It also outlines the hygiene measures that help reduce environmental contamination and the risk to other animals and people in the home.
Cutaneous Histiocytosis
Cutaneous histiocytosis is a reactive condition in which a type of immune cell, the dermal dendritic cell, accumulates in the skin in higher-than-normal numbers, forming visible nodules or plaques. These cells ordinarily sample the environment and communicate with lymphocytes, but in this condition they gather and proliferate in a way that reflects underlying immune dysregulation rather than cancer. Owners typically notice one or more firm lumps or raised patches in the skin, often on the face, trunk, or limbs, and the surface may become ulcerated. The lesions tend to wax and wane over time; some regress on their own, while others persist or recur. The pattern and behaviour often raise questions about what the lumps are, whether they will spread, and what the long-term outlook may be. This page explores what an owner may observe, what is happening beneath the skin, how the condition is investigated and distinguished from other causes of nodules, and the range of approaches used when treatment is pursued. The aim is to provide context for the conversations and decisions that often follow a biopsy diagnosis.
Demodectic Mange
Demodectic mange is a skin condition that develops when microscopic mites, which live in small numbers in the hair follicles of most healthy dogs, begin to multiply beyond the point the immune system can regulate. The mites themselves (Demodex) are typically present from early life and cause no trouble, but when the population expands unchecked, inflammation and hair loss follow. Owners often first notice small patches of thinning fur, particularly around the face, eyes or front legs, sometimes accompanied by reddened or flaky skin. In young dogs, this may appear as the animal matures; in older dogs, it can emerge alongside other illness. The pattern and extent vary widely: from a few localised areas that may resolve without intervention, to more widespread involvement that persists or worsens. This page explores what signs tend to appear, what influences whether the condition stays limited or spreads, how the diagnosis is confirmed, and what treatment approaches exist. It also examines the distinction between cases that remain confined to one or two areas and those that become generalised, as the outlook and management differ considerably between the two.
Dermatomyositis
Dermatomyositis is a condition in which the immune system appears to target both the skin and muscles, leading to inflammation in these tissues. It tends to affect young dogs, usually showing up before six months of age, and appears to run in certain breeds. The underlying cause is not fully understood, but it is thought to involve a combination of genetic vulnerability and immune system behaviour. Owners often notice changes to the skin first: areas of redness, scaling, or hair loss, particularly on the face, ears, and bony points like elbows or the tip of the tail. Some dogs also develop weakness or stiffness, though skin changes are more consistently present. The pattern and severity can vary considerably between individuals, and signs may come and go over time. This page explores what dermatomyositis may look like in practice, what is understood about the processes underneath, how the condition is investigated, and the range of approaches that exist for managing it. The content is designed to help orient thinking, not to diagnose or direct care for an individual animal.
Dermatophytosis (Ringworm)
Dermatophytosis is a fungal infection of the skin, hair, and sometimes claws. The fungi involved, most often a species called Microsporum canis in dogs and cats, live on and digest keratin, the structural protein that makes up the outer layers of skin and the shaft of each hair. This can lead to patchy hair loss, scaling, and sometimes reddened or crusted skin, though the appearance varies widely between individuals. Many owners arrive here after noticing circular areas of thinning fur, broken hairs, or flaky skin, often on the face, ears, or paws. The name "ringworm" refers to the round shape these patches can take, though not every case looks this way, and the infection is caused by a fungus, not a worm. Young animals, those in multi-pet households, and those with other health pressures tend to show signs more readily, though healthy adults can carry the organism without visible change. This page explores what dermatophytosis may look like in practice, how the infection establishes itself and spreads, the ways it can be identified in the clinic, and the range of approaches used to manage it in the home and environment.
Discoid Lupus Erythematosus
Discoid lupus erythematosus is an immune-mediated skin condition in which the body's own immune cells attack the junction where the outer and deeper layers of skin meet. The damage tends to appear in areas exposed to sunlight (most commonly the nose, lips, ears, and around the eyes) and often begins as loss of the normal textured surface of the nose, colour change, or crusting that does not heal in the usual way. Owners often arrive on this page wondering about persistent changes to the nose leather, particularly loss of pigment, scaling, or crusting that may come and go or slowly worsen. In dogs, these changes can sometimes be mistaken for simple sun damage, injury, or infection, but the pattern and location often suggest something happening at a deeper level in the skin. This page explores what signals may be observed, what is happening in the skin when immune cells target the structures at the base of the epidermis, how the condition is investigated through examination and biopsy, and what approaches exist to manage the immune response and protect affected areas.
Distichiasis
Distichiasis describes a pattern in which extra eyelashes grow from abnormal locations along the eyelid margin, typically emerging from the openings of the meibomian glands rather than the usual lash line. These additional lashes often grow inward, making contact with the surface of the eye. The condition can affect one or both eyes and may involve a single aberrant lash or many. Many owners notice their dog squinting, rubbing at the face, or producing more tears than usual. Some animals show no outward signs at all, and the extra lashes are discovered during routine examination. In other cases, the repeated contact between lash and cornea can lead to visible irritation, discharge, or changes in the appearance of the eye surface over time. This page explores the signs that may prompt concern, the anatomical and developmental factors that underlie the condition, the ways in which it is identified and assessed, and the range of approaches used to manage it when intervention is considered appropriate.
Ear Mites
Ear mites are tiny parasites that live in the ear canal, feeding on skin debris and wax. In dogs and cats, the species involved is typically Otodectes cynotis, a mite that can move between animals in close contact and only rarely causes a temporary, itchy rash in people living with infested pets. The mites are barely visible to the naked eye, at most as tiny moving white specks, but their presence often triggers irritation and a characteristic dark, crumbly discharge. Owners most commonly notice persistent head shaking, scratching at the ears, or a dark material that accumulates inside the ear. These signs can appear similar to other ear conditions, and not all itchy ears are caused by mites. Young animals and those in multi-pet households tend to be affected more often, though mites can appear at any age. This page explores what ear mites look like in practice, how they are identified, and the approaches used to address them. It also covers what may happen if mites are left untreated, and why treatment sometimes extends beyond the individual animal showing signs, particularly in households with cats, dogs, or ferrets that share space.
Echinococcus Infection
Echinococcus infection is caused by small tapeworms that live in the intestine of dogs and, very rarely, cats, with different species circulating in different parts of the world. In Great Britain, the historically endemic species is Echinococcus granulosus, which dogs can acquire by eating infected offal or carcasses from sheep or other livestock, a cycle once common in rural parts of mid and south Wales, particularly Powys. A separate species, Echinococcus multilocularis, is carried by foxes and small rodents in parts of mainland Europe but is not established in GB; this is the reason dogs require tapeworm treatment before entering or returning to Britain from most countries abroad. Most dogs with Echinococcus show no outward signs at all, because the worms live quietly in the intestine and are often detected only through routine worming or testing. The primary concern is not usually illness in the dog, but rather the potential for transmission to people, in whom Echinococcus can cause serious internal cysts, a risk managed through regular worming and hygiene measures. This page explores what Echinococcus infection can look like in dogs and cats, how transmission occurs, how the infection is investigated, and the approaches used to treat and prevent it. The focus is on helping owners understand the biology, the public-health context, and the role of routine parasite control.
Ectopic Cilia
Ectopic cilia are individual eyelashes that grow through the inner surface of the eyelid, rather than emerging normally at the lid margin. The hair shaft passes through the conjunctiva (the delicate pink tissue lining the inside of the lid) and rubs directly against the cornea with each blink. This contact causes marked pain and often a corneal ulcer, most often in young dogs, though the condition can appear at any age. Owners most commonly notice their dog squinting, holding one eye partly closed, or producing tears that may look clear or slightly cloudy. The signs often appear suddenly and may affect just one eye. Because the aberrant lash is hidden on the inner lid surface, it is not visible without lifting the lid, which can make the source of discomfort unclear at first glance. This page explores the signals that may suggest ectopic cilia, what happens beneath the surface to produce those signs, how the condition is identified during examination, and the range of approaches used to address it.
Ectropion
Ectropion describes a condition in which the lower eyelid rolls outward, away from the surface of the eye. This creates a visible gap between the lid margin and the eyeball, exposing the pink inner lining of the lid, the conjunctiva, which is moist tissue that normally sits protected. It occurs most often in breeds with loose facial skin or heavy, drooping lower lids, though it can also develop following injury, chronic inflammation, or with age. Owners often notice redness along the lower lid, a persistent watery discharge, or a slightly droopy appearance to the eye. Some dogs develop a habit of pawing at the face, and the exposed tissue may look inflamed or collect debris. The degree of rolling varies; in mild cases the change is subtle, while in others the gap is unmistakable. This page explores the signals that may accompany ectropion, the underlying reasons the lid loses its normal apposition to the eye, how the condition is assessed, and the range of approaches, from managing secondary changes to surgical correction, that may be considered depending on the individual animal and the impact on comfort and eye health.
Ehrlichiosis
Ehrlichiosis is an infection caused by bacteria carried by ticks. These bacteria live inside certain white blood cells and can affect how the immune system functions, sometimes leading to problems with blood cells, clotting, or the body's ability to fight other infections. The condition is seen primarily in dogs that have travelled to or live in regions where specific tick species are found, particularly parts of continental Europe, Africa, Asia, and the Americas. Owners may notice signs from one to three weeks after a tick bite, although some dogs show nothing until months or years later. These can include lethargy, reduced appetite, fever, unexplained bruising or nosebleeds, or swollen lymph nodes. In some cases, signs are subtle or intermittent, and the infection may only be discovered during investigations for other concerns. Some, but not all, infected dogs go on to a chronic phase in which the bone marrow fails, and this form is life-threatening. This page explores the signs that may prompt consideration of ehrlichiosis, what happens inside the body during infection, how the condition is investigated through blood tests and other means, and the approaches used to address it. The focus is on helping owners understand the shape of the condition and the thinking that guides decisions around it.
Eosinophilic Granuloma Complex in Cats
Eosinophilic granuloma complex is a group of skin and mouth conditions in cats that share a common underlying pattern: clusters of immune cells called eosinophils gather in affected tissue, creating characteristic lesions. The name describes what is seen under the microscope rather than a single disease, and the exact trigger often remains unclear even after investigation. Owners typically notice one of several distinct patterns: ulcers on the upper lip, raised plaques on the belly or inner thighs, or thickened areas in the mouth. Some cats show little discomfort, while others may lick or scratch persistently. The appearance can be striking, and it is common to wonder whether the lesion is infectious, cancerous, or self-inflicted. This page explores what these patterns can look like when they first appear, what is understood about the immune processes underneath, how the condition is investigated and distinguished from other causes, and the range of approaches used to manage it. The course varies widely between individuals, and response to treatment can help clarify what is driving the reaction in a particular cat.
Eosinophilic Keratitis in Cats
Eosinophilic keratitis is an inflammatory condition of the cornea (the clear surface of the eye) in which a particular type of immune cell, the eosinophil, accumulates in the tissue. This typically produces pink, white, or chalky raised areas on the cornea, often accompanied by thick discharge that may cling to the eye. The condition can affect one eye or both, tends to appear in adult cats (often around five years of age), and may come and go over time. Owners often notice a change in the appearance of the eye itself (an opaque patch or plaque that was not there before) or persistent discharge that does not clear with routine cleaning. The underlying cause remains uncertain, though the condition is considered immune-mediated and has been observed alongside feline herpesvirus infection in many cases, without proof that the virus directly triggers the corneal change. This page explores what eosinophilic keratitis may look like in practice, the mechanisms thought to be involved, how the condition is investigated (including sampling cells from the cornea), and the range of approaches used to manage inflammation and reduce recurrence. Long-term control, rather than cure, is often the realistic frame.
Eosinophilic Plaque in Cats
Eosinophilic plaque is a type of inflammatory skin lesion that can develop in cats, typically appearing as raised, moist, red areas that often have a raw or eroded surface. The name reflects the presence of a specific type of white blood cell (eosinophils) that accumulates in the affected tissue. These lesions are part of a broader pattern sometimes called the eosinophilic granuloma complex, though the plaque form has its own characteristic appearance and behaviour. Owners most commonly notice eosinophilic plaques as distinct, slightly raised patches on the skin, often on the belly or inner thighs, that may look angry or ulcerated, and which the cat may lick persistently. The lesions can appear suddenly or develop gradually, and their appearance tends to prompt questions about whether the cat has been injured, bitten, or has developed an infection. In many cases, the affected area is intensely itchy, which drives the licking behaviour. This page explores what eosinophilic plaques can look like when they first appear, what processes underneath the skin may be driving them, how they are investigated to understand the cause, and what approaches exist for managing them. The underlying trigger varies between individuals and can include reactions to allergens, parasites, or other factors that provoke the immune response in the skin.
Erythema Multiforme
Erythema multiforme is an inflammatory skin condition in which immune cells (specifically CD8+ T lymphocytes) recognise certain skin cells (keratinocytes) as altered or foreign and trigger those cells to undergo programmed cell death, a process known as apoptosis. This often happens in response to an underlying trigger such as a medication or infection, though in some cases no cause is found. The result is damage at the junction between the outer and deeper layers of the skin, producing a characteristic pattern that pathologists call interface dermatitis. Owners most commonly notice reddened patches, ring-shaped or target-like marks, crusting, or ulceration, particularly at junctions where skin meets mucous membrane (around the lips, eyelids, nose, or genital openings) and sometimes on the paw pads, belly, armpits, or ear flaps. In more extensive cases, patches of skin or the surface of the paw pads may slough, and skin coming away in sheets marks the severe forms described below, which are often fatal. The appearance can be striking, and the condition tends to develop relatively quickly, over hours to days. This page explores what these signs may reflect, what processes unfold beneath the skin, how the condition is investigated through biopsy and history, and what approaches exist to address both the skin changes and any identifiable underlying trigger. The skin reaction itself is not contagious, although an infection that triggered it may be.
Feline Asthma
Feline asthma is a condition in which the airways in the lungs become inflamed and narrowed in response to triggers that would not normally cause trouble. This narrowing makes it harder for air to move in and out, and often leads to coughing, wheezing, or episodes of laboured breathing that can look sudden and alarming. Owners often notice a persistent cough, sometimes described as a hacking or retching sound, or they may see their cat breathing with visible effort, an open mouth, or a crouched posture. These signs can appear out of nowhere or build gradually, and it is not always obvious at first whether what an owner is seeing is something in the airway, the heart, or somewhere else in the chest. This page explores what feline asthma may look like in day-to-day life, what is happening in the airways when it occurs, how it is distinguished from other causes of coughing or breathing difficulty, and the range of approaches used to manage it over time.
Feline Calicivirus
Feline calicivirus is a common cause of respiratory infection and oral ulceration in cats, with strains varying in severity from mild disease to rare but serious systemic illness.
Feline Herpesvirus (FHV-1)
Feline herpesvirus type 1 is one of the primary causes of upper respiratory infection in cats, characterised by sneezing, nasal discharge, and eye problems, with most infected cats becoming lifelong carriers.
Feline Idiopathic Cystitis
A stress-related inflammatory condition of the bladder in cats that causes urinary discomfort without an identifiable infectious cause. In male cats it can lead to a blocked urethra, which is life-threatening.
Feline Immunodeficiency Virus (FIV)
Feline immunodeficiency virus (FIV) is a virus that infects cats and gradually weakens the immune system over a period of years. The virus belongs to the same family as HIV (both are lentiviruses), but FIV is highly species-specific and cannot infect humans, dogs, or other animals. Many cats live for years after infection without obvious illness, though they tend to become more vulnerable to infections and certain other conditions as time passes. Owners often arrive on this page after a positive test result at a routine appointment, or because a cat has been unwell repeatedly with infections that seem slow to clear. Some cats show very little at first; others may have recurring mouth inflammation, skin infections, or weight loss. The virus spreads mainly through deep bite wounds, so outdoor cats and those in multi-cat households where fighting occurs face higher exposure. This page explores what FIV infection can look like over time, how the virus affects the immune system, how infection is confirmed, and the approaches used to support affected cats through different stages of the disease. It also addresses common questions about transmission, testing, and what infection may mean for an individual cat's life.
Feline Stomatitis
Feline stomatitis is a condition in which the soft tissues inside a cat's mouth become severely inflamed. The inflammation typically extends well beyond the gums, often affecting the back of the mouth on either side of the entrance to the throat and the lining of the cheeks. The immune system appears to mount an exaggerated response to bacteria or other triggers in the mouth, and the result is persistent, often painful inflammation that does not resolve on its own. Owners most commonly notice difficulty eating, drooling, a reluctance to groom, or a change in behaviour around mealtimes. Some cats paw at their mouths or withdraw when their face is touched. Weight loss and a foul odour from the mouth are also frequently observed. The signs tend to persist or worsen over time, and many owners arrive at this page after earlier treatments for dental disease have not brought lasting relief. This page explores what stomatitis may look like in day-to-day life, what is understood about the underlying immune dysfunction, how the condition is investigated and distinguished from other causes of mouth pain, and the range of approaches that exist, from medical management to tooth extraction surgery. Each approach carries its own profile of response, duration, and trade-offs.
Flea Allergy Dermatitis
Flea allergy dermatitis describes a pattern of skin inflammation that develops when a dog or cat becomes hypersensitive to proteins in flea saliva. A single flea bite can trigger itching and irritation that persists for several days, often out of proportion to the number of fleas present. The reaction reflects an immune overresponse rather than infestation severity. Owners commonly notice intense scratching, chewing, or licking focused along the lower back, base of the tail, belly, or inner thighs, and in cats also around the head and neck. The skin in these areas may appear red, thickened, or studded with small crusts. Fleas themselves can be difficult to spot, especially in cats or in animals groomed frequently, and many owners arrive uncertain whether fleas have been involved at all. This page explores the visible and behavioural signals that may accompany flea allergy dermatitis, the immune mechanisms that amplify the response, and the investigative approach used to distinguish it from other causes of similar itching. It describes the role of strict flea control in both diagnosis and long-term management, alongside approaches that address the inflammation itself when signs persist.
Food Allergy in Dogs
A food allergy in dogs describes an immune response to a protein in the diet, most often one the dog has been eating without trouble for months or years. The immune system begins to treat that protein as a threat, and the body's reaction tends to show itself through the skin, the gut, or both. It is one of several reasons a dog may become itchy or develop digestive signs, and it can look identical to other conditions at first glance. Owners often arrive here because their dog has been scratching persistently, licking at paws or flanks, developing ear inflammation that returns after treatment, or experiencing recurring soft stools or vomiting. The pattern may feel puzzling because the food has not changed, or because the signs have appeared gradually. Some dogs show skin changes alone, others digestive signs alone, and some experience both. This page explores what food allergy can look like when it first appears, what is happening beneath those signs, how it is investigated through diet trials and observation, and the range of approaches used to manage it long term. The aim is to help you recognise the shape of the condition and understand the reasoning behind the strategies your vet may discuss.
Heartworm Disease in Dogs
Heartworm disease is an infection caused by a parasitic worm (Dirofilaria immitis) that, once mature, lives in the large blood vessels of the lungs and, in advanced cases, the heart itself. The worms are transmitted by mosquitoes, and it can take many months after a bite for the parasite to develop into its adult form. Heartworm is not endemic in the UK, where cases are seen in dogs that have travelled or been imported, but it is widespread in parts of southern and eastern Europe and other warmer regions. Many dogs with heartworm show no outward signs for a long time. When signs do appear, they often relate to the heart and lungs: coughing, tiring more easily on walks, or changes in breathing. In some cases, the first sign is an unexpected finding during routine screening or investigation for something else. The severity of signs tends to reflect how many worms are present and how long the infection has been established. This page explores what heartworm infection can look like in day-to-day life, what happens inside the body as the parasite matures, how the condition is identified through testing and imaging, and the range of approaches used to manage it. It also describes prevention strategies, which are particularly relevant for dogs travelling to or living in regions where heartworm is endemic.
Horner's Syndrome
Horner's syndrome describes a collection of changes to one eye and the surrounding area that occur when certain nerve signals are interrupted. The nerves involved help control the muscles around the eye, the eyelid position, and the size of the pupil. When these signals are disrupted, the eye on the affected side may appear smaller, the pupil may be more constricted than the other, and the third eyelid may become more visible. Owners often notice these changes quite suddenly, though in some cases they develop more gradually. The appearance can be subtle or quite obvious depending on the individual animal. The underlying cause of the nerve disruption varies widely, from ear infections to injuries to conditions affecting the chest or neck, and in many cases no specific cause is identified even after investigation. This page explores the patterns that may be observed, what happens along the nerve pathway to produce these signs, how the condition is investigated, and the range of approaches that may be considered depending on what is found.
Hyphaema
Hyphaema describes blood present in the anterior chamber, the fluid-filled space at the front of the eye, between the cornea and the iris. When blood accumulates there, it may appear as a reddish layer at the bottom of the eye, a diffuse cloudiness, or complete obscuring of normal eye structures. The amount can vary from a faint tinge to a chamber filled entirely with blood. Owners often notice this when the eye appears visibly red inside (distinct from surface redness), when the normally clear front of the eye looks clouded or discoloured, or when the pupil is difficult to see. It can develop suddenly or over hours, and may occur in one eye or both. The blood itself comes from vessels within the eye, though the reason those vessels have bled varies widely, from trauma to inflammation to changes in pressure or clotting. This page explores the patterns that tend to accompany hyphaema, the mechanisms that can lead to bleeding inside the eye, the ways it is investigated, and the approaches used to manage it.
Immune-Mediated Polyarthritis
Immune-mediated polyarthritis describes a pattern in which the body's immune system generates inflammation inside multiple joints. The inflammation is not caused by infection inside the joint or by injury, but by immune activity that has, for reasons often unclear, begun to target the joint tissues themselves. The result is pain, stiffness, and swelling that can appear quite suddenly or build over days. Owners often notice reluctance to move, a stiff or shifting gait, or a dog who seems uncomfortable when rising or navigating stairs. The pattern can affect several joints at once, and the signs may come and go or persist. In some cases, there is a recognisable trigger (an infection elsewhere, a drug, or another immune condition), but in many, the cause remains uncertain. This page explores what these signs can indicate, what may be happening beneath the surface, how the condition is investigated through examination and joint fluid analysis, and the range of approaches used to manage immune-driven joint inflammation over time.
Indolent Ulcer in Cats
An indolent ulcer is a persistent sore that forms on the upper lip of cats, typically starting as a small reddish area that gradually develops into an open, well-defined lesion with raised edges. The term "indolent" reflects the way these ulcers behave: they tend to grow slowly and often seem painless, though the underlying tissue is inflamed and the surface does not heal in the usual way. The cause involves an abnormal immune response in the skin, though the exact trigger in an individual cat is not always clear. Owners often notice a thickened or eroded patch on one or both sides of the upper lip, sometimes with a glistening or raw appearance. The cat may not seem particularly bothered by it, and there may be no obvious change in eating or grooming. The lesion can remain stable for weeks or months, or it may gradually enlarge if left unaddressed. This page explores the signs that may suggest an indolent ulcer, what is understood about the underlying process in the lip tissue, how the condition is typically investigated, and the range of approaches that exist for managing it. The focus is on helping you understand what may be happening and what shape a conversation with your veterinary team might take.
Infectious Tracheobronchitis (Kennel Cough)
Infectious tracheobronchitis is an inflammation of the windpipe and airways caused by viruses and bacteria, often several together, that spread easily between dogs in shared spaces. The hallmark is a persistent, dry, hacking cough that can sound harsh or honking, often triggered by excitement, exercise, or pressure on the throat. Many dogs remain otherwise well (eating, playing, and behaving normally), though some develop a softer cough with mucus, reduced energy, or a slight fever. Owners often arrive at this page after noticing a sudden-onset cough following recent contact with other dogs at kennels, parks, grooming salons, or training classes. The cough may be alarming in its intensity, but the dog's overall demeanour tends to be reassuring. In a smaller number of cases, particularly in young puppies, older dogs, or those with other health considerations, the infection can extend deeper into the lungs. This page explores what infectious tracheobronchitis looks like in practice, the organisms involved and how they interact, the way cases are assessed and investigated, and the range of approaches used to support recovery and limit spread. It also considers when signs may warrant closer attention and what influences the course and outcome in different animals.
Inflammatory Bowel Disease in Cats
A chronic condition involving inflammation of the gastrointestinal tract that affects digestion, appetite, and nutrient absorption in cats.
Inflammatory Bowel Disease in Dogs
A chronic gastrointestinal condition involving persistent inflammation of the digestive tract that affects nutrient absorption and comfort.
Juvenile Cellulitis (Puppy Strangles)
Juvenile cellulitis is an uncommon skin condition that affects young puppies, typically between three weeks and four months of age. It involves sudden inflammation of the skin on the face, particularly around the muzzle, eyes, and ears, often accompanied by swelling of the lymph nodes under the jaw. The condition is thought to involve an immune system response rather than infection, though the exact trigger remains unclear. Owners often notice that their puppy's face has become puffy or swollen, sometimes quite dramatically, with the skin feeling warm or developing small pustules. The ears may also be affected. Some puppies are unwell in themselves, with lethargy, a fever or loss of appetite. Swelling and pustules can extend across the face, eyelids and ears over a few days. Where severe lesions develop, particularly around the eyes, scarring and hair loss can be permanent. Most puppies recover fully when treatment starts early, and how deep the inflammation has reached cannot be judged by looking at the face at home. This page explores what signs may appear, what is understood about the underlying process, how the condition is investigated and distinguished from other causes of facial swelling in young dogs, and what treatment approaches exist.
Kennel Cough in Dogs
Kennel cough describes a harsh, distinctive cough that develops when the airways (the windpipe, or trachea, and the larger airways, or bronchi) become inflamed, often after contact with other dogs. The inflammation can be triggered by a range of infectious agents, sometimes several at once, and tends to appear a few days after exposure in places where dogs congregate. The cough itself is typically dry and forceful, sometimes described as honking or as though something is caught in the throat, and it may be the only sign an owner notices. Many dogs remain bright and eating normally throughout, while others develop a softer cough, nasal discharge, or a period of reduced appetite. The intensity and duration can vary considerably depending on which pathogens are involved, the dog's age and vaccination history, and whether complications develop. Puppies, older dogs, and those with existing airway or immune conditions may experience a more pronounced or prolonged course. This page explores what kennel cough looks like in practice, the infectious agents and immune responses that underlie it, how veterinary surgeons distinguish it from other causes of coughing, and the range of approaches used to support dogs through the illness. It also considers when the clinical picture suggests a need for closer monitoring or investigation.
Keratoconjunctivitis Sicca (Dry Eye)
Keratoconjunctivitis sicca describes what happens when the tear glands produce too little of the watery layer that normally keeps the eye moist. Without enough tears, the surface of the eye becomes dry and inflamed, and the body often compensates with a thick, sticky discharge that can look quite different from healthy tearing. In many dogs the condition develops gradually over months. It can also begin suddenly, for example during treatment with certain sulphonamide medicines, and in that situation a corneal ulcer can be present from the start. Owners often notice a change in the appearance of the eye itself: a dull or cloudy look to the surface, discharge that is yellow or green rather than clear, redness, squinting, or a sense that the eye looks uncomfortable. Some arrive wondering about recurring 'eye infections' that never quite clear, or about one eye that looks different from the other. The signs can wax and wane early on, which sometimes delays recognition. This page explores what dry eye can look like in its different stages, what drives the loss of tear production, how the diagnosis is made, and the range of approaches used to manage it over time. The aim is to help you understand what may be happening and what shape that management might take.
Leishmaniasis
Leishmaniasis is an infection caused by a microscopic parasite called Leishmania, transmitted through the bite of certain sandflies. The parasite can spread through the body and may affect the skin, internal organs, or both, depending on how the immune system responds. It is most commonly seen in dogs that have travelled to or lived in regions where these sandflies are present, particularly southern Europe and parts of the Mediterranean. Owners often first notice skin changes (such as hair loss, scaling, or sores that do not heal) or more general signs like weight loss, lethargy, or changes in appetite. Some dogs show few or no signs for months or even years after exposure, while others develop a range of problems relatively quickly. The signs can be subtle and may develop gradually, which sometimes makes the picture unclear at first. This page explores the patterns that may raise the possibility of leishmaniasis, what is happening inside the body when the parasite is present, how the infection is investigated through blood tests and other methods, and the range of approaches that exist for managing it over time.
Leptospirosis
Leptospirosis is an infection caused by bacteria of the Leptospira group, which can affect multiple organs in dogs and, more rarely, cats. The bacteria are typically spread through contact with contaminated water or soil, often where infected wildlife has urinated. In many cases the infection produces mild signs or none at all, but in others it can lead to serious illness affecting the kidneys, liver, lungs, or other systems. Owners may notice a range of signs, from lethargy, reduced appetite, and fever in milder cases, to vomiting, increased thirst, jaundice, or difficulty breathing in more severe presentations. The picture varies considerably depending on which organs are involved and how the individual animal responds. Some dogs are diagnosed after routine blood tests show changes in kidney or liver function, even before obvious signs appear. This page explores the signs that may prompt concern, what is happening inside the body during infection, how leptospirosis is investigated through blood tests and other tools, and the approaches used to support affected animals. It also considers prevention, including vaccination, and the broader context of risk in different environments.
Lyme Disease (Borreliosis)
Lyme disease is an infection caused by bacteria of the Borrelia burgdorferi sensu lato group, transmitted when an infected tick feeds on a dog or cat for a prolonged period. The condition is named after a town in Connecticut where it was first recognised in people, and the bacteria are carried by Ixodes ticks in the UK and much of Europe. In pets, the infection can remain silent for weeks or months, or it may trigger signs that range from intermittent lameness and joint pain to more generalised illness. Many owners arrive at this page because their pet has been found to carry ticks after woodland walks, or because a limp has appeared and disappeared without obvious injury, or because a blood test has returned a positive result. Cats can test positive for antibodies, but it is not known whether the infection makes them ill. Dogs can develop shifting leg lameness, lethargy, or occasionally signs of kidney involvement. This page explores what Lyme disease can look like in dogs, how the bacteria behave once inside the body, the ways in which infection is detected and distinguished from other causes of similar signs, and the range of approaches used when treatment is considered appropriate.
Lyme Nephritis
Lyme nephritis is a rare but serious kidney condition that can develop in some dogs exposed to the Lyme disease bacterium, *Borrelia burgdorferi*. Rather than a direct infection of the kidneys, it appears to arise when immune complexes (clumps of antibody and bacterial antigen) lodge in the delicate filtering structures of the kidney, triggering inflammation and progressive loss of the kidney's ability to retain protein. The result is a protein-losing nephropathy: protein leaks into the urine, blood protein levels fall, and fluid may begin to accumulate in the tissues or abdomen. Owners often arrive at this page because their dog has become unwell quite quickly, perhaps drinking and urinating more than usual, losing appetite and weight, appearing lethargic, or developing visible swelling. In its classic form the disease progresses rapidly, and in the series of cases that first defined it every dog died. The condition tends to appear in young to middle-aged dogs, and Labrador Retrievers and Golden Retrievers appear more susceptible. This page explores the outward signals that may be observed, the immune and kidney changes happening beneath them, the investigations used to build a picture of what is occurring, and the range of supportive and disease-modifying approaches that exist. It does not tell you what your dog has; it offers a framework for understanding what Lyme nephritis is and how it is approached in veterinary medicine.
Lymphoma in Cats
Lymphoma is a cancer that arises from lymphocytes, a type of white blood cell that ordinarily helps protect the body from infection. In cats, these cells can begin to multiply uncontrollably in lymph nodes, the digestive tract, the chest, the kidneys, the nose, the eyes, the skin, or the nervous system. The disease can appear in many forms, and the signs an owner notices often depend on which part of the body is most affected. An owner may observe weight loss, reduced appetite, vomiting, diarrhoea, difficulty breathing, a lump under the jaw or behind the knee, or changes in behaviour. Sometimes a cat appears generally unwell without an obvious focal problem. Because lymphoma can involve almost any organ, the pattern of signs varies widely, and the route to investigation often begins with bloodwork, imaging, or sampling tissue from an affected site. This page explores what lymphoma can look like in its different forms, what may be happening inside the body, how the diagnosis is typically reached, and the range of approaches that exist, including chemotherapy, palliative care, and monitoring. The course and response can differ considerably depending on the type and location of disease.
Lymphoma in Dogs
A cancer of the lymphatic system that can present in multiple forms and locations, affecting organ function and wellbeing.
Malassezia Dermatitis
Malassezia dermatitis occurs when a yeast that normally lives in small numbers on the skin begins to overgrow, often in response to changes in the skin's environment or defences. The yeast itself is not an invader. It is part of the usual population of microbes found on most dogs, but when conditions shift, it can multiply and trigger inflammation, odour, and discomfort. Owners often notice a distinctive sweet or musty smell, particularly around the ears, paws, or skin folds, along with redness, greasiness, or persistent scratching. The signs can develop gradually or appear after changes in weather, bathing routines, or alongside other skin conditions. What looks like a straightforward infection may be the visible part of a more complex shift in the skin's balance. This page explores the signals that suggest Malassezia overgrowth, the factors that can tip the skin's ecosystem out of balance, how the condition is confirmed, and the range of approaches used to bring the yeast population back under control and address any underlying contributors.
Mastitis
Mastitis is inflammation of one or more mammary glands, most commonly seen in female dogs and cats during lactation or in the period shortly after weaning. The affected gland may become swollen, warm, firm, or discoloured, and milk expressed from it can appear abnormal: thickened, bloodstained, or otherwise changed in appearance. Owners often notice these changes when a nursing mother seems uncomfortable, when puppies or kittens appear restless or are not gaining weight as expected, or when routine handling reveals a gland that feels different from the others. Mastitis can range from mild localised changes to severe infection in which part of the gland forms an abscess or dies, bacteria enter the bloodstream, and both the mother's life and the litter are at risk. When signs extend beyond the gland itself, with the nursing animal quieter, feverish, off her food, vomiting, or reluctant to allow feeding, this points to the more serious end of that range. This page explores the signals that can accompany mastitis, the biological processes that contribute to inflammation in mammary tissue, the ways in which the condition is investigated, and the range of approaches used to support affected animals and their offspring during the nursing period.
Mosquito Bite Hypersensitivity in Cats
Mosquito bite hypersensitivity in cats is an exaggerated immune response to proteins in mosquito saliva. When a mosquito feeds, it injects saliva containing anticoagulants and other substances; in susceptible cats, the immune system responds more intensely than typical, leading to persistent inflammation at bite sites. The condition is most commonly seen in areas where mosquitoes are active, and tends to affect outdoor cats or those in homes with access to gardens during warmer months. Owners typically notice crusted, scabby lesions on areas with less fur, particularly the nose and ears, and less often the paw pads, that may appear after mosquito exposure. The affected skin can look red, swollen, or ulcerated, and the lesions may be itchy or uncomfortable. Because the distribution often follows a pattern (exposed, thinly furred areas), the appearance can raise questions about what might be causing these recurring changes. This page explores what mosquito bite hypersensitivity can look like in practice, the immune mechanisms that drive the reaction, how the condition is distinguished from other causes of facial and ear lesions, and the range of approaches used to manage symptoms and reduce exposure. The focus throughout is on understanding what may be happening and what options exist, rather than diagnosing any individual cat.
Optic Neuritis
Optic neuritis is inflammation of the optic nerve, the structure that carries visual information from the eye to the brain. When this nerve becomes inflamed, it can disrupt the transmission of signals, and animals may show changes in vision or behaviour that suggest they are not seeing clearly. The inflammation may affect one eye or both, and the onset can be gradual or relatively sudden. Owners often notice that their pet is bumping into objects, hesitating in familiar spaces, or showing a change in how they navigate, and the change can develop over hours to a few days. Some animals may have a visible change in the appearance of the eye itself, while in others the eye looks entirely normal from the outside. The underlying cause of the inflammation varies; in some cases it appears to be part of a broader immune or inflammatory process, while in others no clear trigger is identified. This page explores the signals that may prompt concern, the mechanisms that can lead to optic nerve inflammation, the investigations that help clarify what is happening, and the range of approaches that exist. The goal is to orient you to the condition and the questions that may arise during assessment and management.
Otitis Externa in Cats
Otitis externa is inflammation of the external ear canal, the passage that runs from the visible ear opening down to the eardrum. In cats, it often appears as head shaking, ear scratching, or a darkened discharge visible at the ear opening, though some cats show little outward sign until the problem is quite developed. Owners typically notice their cat flicking one or both ears, holding one ear lower than the other, or resisting touch around the ear. The discharge may be dry and crumbly, waxy and brown, or occasionally moist, depending on what is driving the inflammation. Ear mites are a common trigger in younger cats, while allergies, foreign material, polyps, and skin conditions play a role in others. Less commonly, the problem reflects an underlying immune-mediated condition. This page explores what prompts inflammation in the feline ear canal, what signals may be observed, how the ear is examined and sampled, and the range of approaches used to address both the inflammation itself and whatever is sustaining it.
Otitis Externa in Dogs
Inflammation of the external ear canal, often involving bacterial or yeast overgrowth, that causes discomfort, discharge, and changes in ear-related behaviour.
Otitis Interna
Otitis interna refers to inflammation or infection that has reached the inner ear, the deepest part of the ear system, where structures responsible for balance and hearing are located. It often develops when infection spreads inward from the middle ear or, less commonly, arrives through the bloodstream. Because the inner ear houses the vestibular apparatus, which helps the body sense position and movement, disruption here tends to produce signs that many owners find striking: a head tilt, loss of balance, circling, or rapid involuntary eye movements. Owners often arrive at this page because their dog or cat has suddenly developed a pronounced lean to one side, difficulty walking in a straight line, or seems unable to stand without falling. These signs reflect the inner ear's role in spatial orientation. In some animals, the process begins with visible outer or middle ear disease; in others, the inner ear involvement is the first obvious signal. This page explores what those signs can look like, what may be happening beneath them, how the inner ear is examined and imaged, and the range of approaches (medical and occasionally surgical) that exist to address the underlying cause and support recovery.
Otitis Media
Otitis media refers to inflammation within the middle ear, the small, air-filled chamber that sits behind the eardrum. This space is normally sealed off from the outside world, but inflammation here can arise when infection or other processes extend inward from the external ear canal, or, more often in cats, when material travels up through the tube that connects the middle ear to the back of the throat. Because the middle ear sits close to important structures including nerves and the inner ear, changes here can produce effects that extend beyond what an owner might associate with a typical ear problem. Many owners first notice signs that overlap with outer ear inflammation (head shaking, ear discomfort, or discharge), but some dogs and cats show additional patterns such as a head tilt, reluctance to open the mouth fully, or changes in balance. In other cases, otitis media is identified during investigation of a persistent or recurring outer ear problem that has not responded as expected. The condition is not always obvious from the outside, and the signs an owner observes often depend on whether the eardrum remains intact and how much the inflammation affects neighbouring structures. This page explores the signals that can appear when the middle ear is involved, the mechanisms that allow inflammation to develop in this normally protected space, the ways otitis media is investigated and confirmed, and the range of approaches used to address it. The goal is to help owners understand what may be happening and what shape the conversation with their veterinary team might take.
Pannus (Chronic Superficial Keratitis)
Pannus is a condition in which the immune system begins to treat part of the eye's surface as something foreign, leading to inflammation and the gradual appearance of a pigmented, fleshy tissue that can grow across the cornea. It tends to start at the outer edge of the eye and move inwards over time, and both eyes are often affected, though not always at the same rate. Certain breeds, particularly German Shepherd Dogs and their relatives, develop this condition more often than others, and it is sometimes referred to as chronic superficial keratitis. Owners often notice a dark or reddish discolouration beginning at the corner of the eye, or a hazy, thickened appearance to the clear part of the eye. Some dogs have a slight mucoid discharge. Pannus itself is not usually painful, so squinting or rubbing at the eye points towards another problem, such as a corneal ulcer. The changes can be subtle at first and may be mistaken for a simple irritation or ageing. This page explores what an owner may observe, what is happening beneath the surface, how the condition is investigated, and the range of approaches used to manage it over time.
Pemphigus
Pemphigus is a group of autoimmune skin diseases in which the immune system produces antibodies against proteins that normally hold skin cells together. When those connections break down, small pus-filled blisters (pustules) form in the outer layers of the skin. These pustules are fragile and rupture quickly, so what an owner typically observes is not intact pustules but crusts, scales, and raw or weeping patches, most commonly around the face, ears, and paws. Many owners arrive wondering about persistent scabs that do not heal in the usual way, or skin that seems to peel or crust in waves. In dogs, the most common form targets a protein called desmocollin-1; in cats, the precise target is less well characterised, but the pattern of disease can be similar. Pemphigus can affect animals of any age, though certain breeds may be seen more often. Pemphigus foliaceus, the superficial form described here, is the form seen most often. A rarer, deeper form, pemphigus vulgaris, causes painful ulcers in the mouth and where skin meets moist lining, such as the lips, eyelids, anus and vulva; it is a severe illness that is often fatal. This page explores what pemphigus may look like in day-to-day life, the biology underneath the visible changes, how the condition is investigated and confirmed, and the range of approaches used to manage it over time.
Pneumonia
Pneumonia is inflammation of the lung tissue, most often involving bacterial infection. It is a common diagnosis in dogs, frequently following inhalation of food, vomit or regurgitated material, a viral or bacterial respiratory infection such as kennel cough, or an inhaled foreign body such as a grass awn. It occurs less often in cats, and laboured breathing in a cat is more often due to heart failure, which can look very similar from the outside. Signs range from a moist cough, quietness and poor appetite to laboured breathing. Fever is detected in only around 16 to 50 per cent of cases, and a cat's cough can be mistaken for retching, so the absence of either does not rule pneumonia out. Chest X-rays are central to confirming it, although changes can lag behind the signs. Some forms, including a haemorrhagic streptococcal pneumonia seen in dogs, can progress to severe illness or sudden death.
Progressive Retinal Atrophy
Progressive retinal atrophy describes a group of inherited conditions in which the light-sensing cells at the back of the eye gradually stop working. The retina, which converts light into signals the brain can interpret, slowly loses function over months to years, and this process cannot currently be reversed. Owners often first notice changes in dim light or unfamiliar places: a dog may hesitate on evening walks, bump into furniture after dark, or seem less confident navigating new environments. In familiar settings, many animals adapt so well that the change can go unnoticed for some time. The pupils may appear more dilated than usual, and in some cases a shine or reflective change is visible in the eye. This page explores what these changes can look like in day-to-day life, what is happening within the retina as cells deteriorate, how the condition is identified through examination and testing, and what approaches exist to support an affected animal as vision declines.
Pyoderma
Pyoderma describes bacterial infection of the skin. It develops when bacteria (most often those that live harmlessly on the surface in healthy animals) multiply within the layers of the skin itself, triggering inflammation and damage. The infection can be confined to the very surface, or it can extend deeper into the tissue. Owners often notice redness, small raised bumps, crusting, or circular patches where the hair has thinned or fallen away. Some dogs develop a distinctive smell, or the skin may feel warm or thickened in affected areas. Itching is common, though not always present. The pattern and extent can vary widely, from a few isolated spots to large areas of the body. This page explores what pyoderma can look like in different forms, what tends to lie beneath it (including factors that allow bacteria to take hold) and how it is investigated and approached. The aim is to help you understand what may be happening when skin infection is part of the picture.
Pyoderma in Dogs
Pyoderma is a bacterial infection of the skin. It occurs when bacteria, most often those that live harmlessly on the skin's surface under normal conditions, multiply within or beneath the outer layers and trigger inflammation. The depth and pattern of that infection shape what an owner observes. Many owners notice redness, small raised bumps, crusts, or circular patches of hair loss. Some dogs develop a distinctive smell or begin licking or scratching at affected areas. The appearance can range from a few scattered spots to widespread change across the body, and the signs can look very different depending on whether the infection involves only the surface or extends into deeper layers of skin. This page explores the signals that may point towards pyoderma, the factors that allow infection to take hold, how the condition is investigated, and the range of approaches used to address it, including topical treatments, systemic options, and the management of underlying contributors.
Pyometra
Pyometra is a condition in which the uterus fills with pus, typically in the weeks following a season. It arises when hormonal changes after ovulation create an environment in which bacteria can multiply unchecked within the uterine lining. The condition occurs almost exclusively in unspayed female dogs and cats, and tends to appear in middle-aged or older animals, though younger individuals can be affected. Owners often notice a combination of signs that may include drinking more than usual, lethargy, reduced appetite, or, in some cases, a thick discharge from the vulva. In other animals the cervix remains closed and no discharge is visible, which can make the picture less clear. The abdomen may appear distended, and some animals develop vomiting or seem generally unwell in ways that are difficult to pinpoint. This page explores what can signal pyometra, the mechanisms that allow infection to take hold, how the condition is investigated through examination and imaging, and the medical and surgical approaches used to address it. It also considers what influences outcomes and what owners may observe during recovery.
Retinal Detachment
Retinal detachment describes the separation of the retina, the light-sensitive layer at the back of the eye, from the tissue beneath it. When this happens, the retina can no longer function normally, and vision is affected. In dogs and cats, this can occur suddenly or develop over time, and may affect one eye or both. Owners often notice changes in how their pet moves through familiar spaces: hesitation, or bumping into furniture and other objects. Sight is often lost suddenly, and in cats usually in both eyes. In other cases these signs develop more gradually, depending on what is driving the detachment. The pupil may appear unusually large, and in some cases the eye itself may look different: cloudy, with blood inside, or with visible changes behind the clear front surface. This page explores what these changes in vision and eye appearance can signal, the range of underlying processes that can lead to retinal detachment, how the condition is investigated through examination and imaging, and the approaches that exist once a detachment has been identified.
Salmonellosis
Salmonellosis is an infection caused by Salmonella bacteria, which can affect the gastrointestinal tract and, in some cases, spread more widely through the body. These bacteria are found in many environments and can be carried by animals without causing illness, but they may also trigger disease, particularly in young animals, those with weakened immune systems, or pets under stress. In dogs and cats, infection often follows ingestion of contaminated food, water, or material from the environment. Owners most commonly notice sudden onset of diarrhoea, which may contain blood or mucus, often accompanied by vomiting, reduced appetite, and lethargy. Some animals show mild signs that resolve quickly, while others become unwell enough that dehydration or systemic effects develop. Occasionally, a pet may carry the bacteria without appearing ill, raising questions about household risk or transmission. This page explores the signs that may prompt concern, what happens in the body during infection, how the condition is investigated through laboratory testing and clinical assessment, and the range of supportive and antimicrobial approaches that may be considered depending on severity and individual factors.
Sarcoptic Mange
Sarcoptic mange is a condition in which microscopic mites burrow into the outer layers of the skin, triggering intense itching and inflammation. The mites themselves are not visible to the eye, but the body's reaction to them often is: many owners first notice scratching that seems relentless, hair loss in patches, and skin that may appear red, thickened, or crusted. The itch tends to be severe enough that it disrupts rest and daily life. Because the mites can spread between animals and sometimes cause temporary irritation in people, owners may also be navigating questions about other pets in the household or mild skin changes they have noticed themselves. The signs can sometimes resemble other skin conditions, which is why the path to clarity often involves specific testing. This page explores what sarcoptic mange may look like when it first appears, what is happening beneath the skin, how the condition is identified, and the range of approaches used to address it. The aim is to help you understand the patterns, the questions that guide investigation, and the timeframes involved.
Sebaceous Adenitis
Sebaceous adenitis is an inflammatory condition affecting the sebaceous glands in the skin: the small structures that produce oils to keep the coat and skin supple. In this condition, the body's immune system appears to target these glands, leading to their gradual destruction. The result is skin that becomes dry, scaly, and less able to maintain its normal protective barrier. Owners often notice changes in coat quality first: the fur may become dull, brittle, or matted, with white or silver scales clinging to the hair shafts, particularly along the back, head, and ears. Some dogs develop patchy hair loss, a musty odour, or areas where the skin feels thickened. The pattern and severity vary considerably between individuals, and in some cases the changes are subtle and slow to develop. This page explores what sebaceous adenitis may look like in practice, the processes thought to drive it, how veterinary surgeons investigate and confirm it, and the range of approaches used to manage skin health over time.
Skin Fold Dermatitis
Skin fold dermatitis describes inflammation that develops in areas where skin folds back on itself, creating a warm, moist environment that can support bacterial or yeast overgrowth. It most often occurs in deep facial folds, lip folds, tail folds, vulvar folds, or between the toes in certain breeds. The overlapping skin traps moisture, oils, and debris, which can lead to irritation, odour, and infection. Owners often notice redness, dampness, or a distinctive smell in the affected folds, and may see their dog or cat rubbing or scratching at the area. Some folds show only mild discolouration, while others develop crusting, discharge, or hair loss. The problem can be intermittent or persistent, and tends to recur if the underlying anatomy and moisture are not managed. This page explores the patterns that may appear, what is happening in the skin and fold environment, how the condition is confirmed and monitored, and the range of approaches, from routine care to surgical correction, that may be considered depending on the severity and location.
Sterile Nodular Panniculitis
Sterile nodular panniculitis is a condition in which the layer of fat beneath the skin becomes inflamed, forming firm lumps or nodules that can appear anywhere on the body. The inflammation occurs without infection: the word sterile refers to the absence of bacteria or other infectious agents. The immune system appears to be reacting to the fat tissue itself, though the precise trigger is not always clear. Owners often notice one or more raised, firm areas under the skin that may feel warm, appear reddened or discoloured, and sometimes open to discharge an oily or fatty material. These nodules can develop gradually or appear quite suddenly, and they may occur as isolated lumps or in clusters. The condition can affect dogs of any age or breed, though certain patterns have been observed in specific groups. This page explores the signals that may prompt consideration of sterile nodular panniculitis, the mechanisms that drive inflammation in the fat layer, the investigations used to distinguish it from other causes of skin lumps, and the approaches available for managing the condition over time.
Steroid-Responsive Meningitis-Arteritis (SRMA)
Steroid-responsive meningitis-arteritis is an inflammatory condition in which the body's immune system targets the membranes surrounding the brain and spinal cord, and the blood vessels that supply them. It occurs most often in young dogs, usually between 6 months and 2 years of age, and certain breeds, including Beagles, Boxers, and Bernese Mountain Dogs, are seen more frequently than others. The inflammation tends to develop over hours to days, and can recur in waves even after treatment has begun. Owners often arrive at this page because their dog has developed neck pain that makes them reluctant to lower their head, along with fever and a general sense of being unwell. Some dogs also show stiffness, a hunched posture, or reduced appetite. The signs can look similar to other causes of neck pain or systemic illness, which is why the underlying cause needs to be identified through testing. This page explores what signs may be observed, what is happening in the nervous system and blood vessels, how the condition is investigated through blood tests and analysis of spinal fluid, and what approaches exist to manage the inflammation and reduce the chance of recurrence.
Sudden Acquired Retinal Degeneration Syndrome (SARDS)
Sudden Acquired Retinal Degeneration Syndrome, often referred to as SARDS, describes a pattern in which a dog loses vision over a period of days to weeks, often quite rapidly, due to changes in the light-sensing layer at the back of the eye. The retina stops working properly despite the eye itself appearing structurally normal on initial examination. The underlying cause remains poorly understood, though immune-mediated processes are among the possibilities considered. Owners typically notice that their dog has become hesitant to move in dim light or unfamiliar spaces, may bump into objects, or seem suddenly uncertain in environments they previously navigated with ease. The change can feel abrupt: a dog who was seeing normally one week may appear functionally blind the next. Many dogs otherwise seem well in themselves at the time vision loss is noticed, though more than half show increased thirst, appetite, or weight in the weeks surrounding the onset. This page explores what signs tend to appear and in what timeframe, what is understood about the processes that may lead to retinal dysfunction in SARDS, how the condition is investigated and distinguished from other causes of vision loss, and what approaches exist for supporting a dog living without sight.
Symmetric Lupoid Onychodystrophy
Symmetric lupoid onychodystrophy is a condition in which the immune system appears to target the structures that anchor and grow the claws, leading to progressive claw loss and abnormal regrowth. It tends to affect multiple claws at once, often in a symmetrical pattern across the paws, and can involve all of the claws over time. The term "lupoid" reflects microscopic features in biopsy samples that resemble lupus. The disease is not systemic lupus and causes no signs elsewhere in the body. Pain, lameness or shed claws found around the house are often the first things owners notice. Claws may also become brittle, discoloured, or begin to separate from the nail bed, sometimes with discharge. In many cases, claws may fall off entirely and regrow in a distorted or fragile form. The pattern of involvement and the way the claws look as they regrow can raise questions about infection, injury, or other claw disorders. This page explores the signals that may prompt consideration of this condition, what is understood about the immune processes involved, how the diagnosis is approached, and the range of management strategies that exist. The course and response to treatment can vary, and the aim of the page is to help orient your understanding of what may be happening and what the journey ahead might involve.
Toxic Epidermal Necrolysis
Toxic epidermal necrolysis is a rare, life-threatening condition in which large areas of the skin begin to separate and shed, often quite suddenly. The body's immune system mounts an intense reaction that kills the cells of the outer layer of skin so that it detaches from the tissue beneath, and this can extend to the mucous membranes inside the mouth, around the eyes, and in other areas. It tends to appear as reddened skin that develops blisters or sheets of skin that peel away, and the affected areas can be painful and vulnerable to infection. Owners most commonly notice widespread skin lesions that seem to appear rapidly, most often after a medication has been given and less often alongside an infection or a tumour, though in some cases no trigger is identified. The extent of skin involvement can vary, and areas that look initially inflamed may progress to more obvious peeling or raw patches over hours to days. This page explores the patterns that may raise concern for toxic epidermal necrolysis, the immune and cellular processes understood to drive the condition, how it is distinguished from other causes of severe skin damage, and the range of approaches used to support affected animals whilst the skin begins to heal.
Toxoplasmosis
Toxoplasmosis is an infection caused by a single-celled parasite called Toxoplasma gondii. Cats and other members of the cat family are the only animals in which the parasite completes its life cycle and passes eggs (oocysts) in faeces. Many cats carry it without showing signs of illness, but some, particularly kittens and cats with weakened immune systems, develop illness that can be severe. Dogs can also become infected, though they do not produce oocysts, and clinical illness is less common than in cats. Owners often arrive at this page because routine testing has detected exposure to the parasite, or because their pet is unwell and toxoplasmosis has been mentioned as one possibility. Signs, when they occur, can vary widely depending on which part of the body is affected: the eyes, lungs, nervous system or muscles. In many cases, the infection remains dormant and causes no trouble at all. This page explores what toxoplasmosis can look like in dogs and cats, what is happening in the body when infection occurs, how it is identified through testing, and the range of approaches that exist when treatment is considered. The goal is to help you understand the condition and the questions that shape decisions around it.
Triaditis in Cats
Triaditis describes a pattern in which three neighbouring organs in a cat's abdomen (the pancreas, the liver and its bile ducts, and the small intestine) become inflamed at the same time. In cats these structures sit very close together and share connections, which may allow inflammation in one to involve the others. It is one of the reasons a cat may show signs that seem vague or difficult to pinpoint. Owners often notice a cat becoming quieter, eating less, or losing weight over weeks to months, though some cats show more sudden changes. Vomiting is common. Signs of abdominal pain, such as a tucked or hunched posture, are recorded in 10% to 30% of cats with pancreatitis, and many cats simply seem less themselves. Because the pattern involves multiple organs, the picture can shift or broaden over time. This page walks through what triaditis can look like in day-to-day life, what happens inside the body when these three organs become inflamed together, how the pattern is investigated through blood tests and imaging, and the ways the inflammation can be managed. The goal is to help you understand what may be unfolding and what the process of working through it typically involves.
Tritrichomonas Foetus in Cats
Tritrichomonas foetus is a microscopic single-celled organism that can live in the large intestine of cats, most often causing persistent diarrhoea that may contain mucus or small amounts of blood. It spreads through direct contact with infected faeces, so it tends to be seen more commonly in young cats from multi-cat environments such as breeding catteries or shelters, though cats of any age living in any setting can be affected. Some cats carry the organism without showing signs at all. Owners typically notice loose or semi-formed stools that persist for weeks or months, sometimes improving briefly before returning. The cat often remains otherwise well (eating normally, maintaining weight, and behaving as usual), which can make the pattern puzzling. In some cases the diarrhoea resolves on its own over time, while in others it continues or recurs. This page explores what signs may appear, what is happening in the intestine when this organism is present, how it can be identified through testing, and what approaches exist for managing the condition. The goal is to help you understand the range of possibilities and what conversations may be useful as you and your vet work through the picture your cat is showing.
Urinary Tract Infection in Dogs
A urinary tract infection occurs when bacteria establish themselves in parts of the urinary system: most often the bladder, sometimes the urethra, and occasionally further up in the kidneys. The infection can cause inflammation and discomfort, and may change the way urine looks, smells, or is passed. Owners often notice more frequent trips outside, straining or discomfort when urinating, or small amounts of urine produced each time. Straining that produces only drops of urine or none at all is a different and more serious picture, because it can mean the urethra is blocked. The urine itself may appear cloudy, bloodstained, or have a stronger smell than usual. Some dogs show no outward signs at all, and the infection is found during routine testing for another reason. This page explores what these patterns can signal, what may be happening in the urinary tract, how infections are identified through testing, and the range of approaches used to address them, including when additional investigation may be warranted.
Uveitis
Uveitis describes inflammation inside the eye, affecting structures that lie beneath the outer surface: the iris, the ciliary body, and the choroid. These tissues are rich in blood vessels and immune cells, which means inflammation here can arise from infection, immune reactions, injury, or processes elsewhere in the body that have reached the eye through the bloodstream. Owners often notice a red or clouded eye, squinting, sensitivity to light, or a change in the appearance of the iris or pupil. The eye may look uncomfortable, and in some cases the surface can appear hazy or the pupil unusually small. These signs can develop quickly or build gradually, and they can affect one eye or both. This page explores what uveitis can look like from the outside, the range of processes that can trigger inflammation inside the eye, how the condition is investigated, and the approaches used to manage it. The aim is to help you understand what may be happening and what shape assessment and care tend to take.
Vaginitis
Vaginitis describes inflammation of the vagina. It is seen mainly in dogs and only rarely in cats. Young female dogs may develop it before their first season, while in adult animals it often appears alongside other changes in the reproductive tract or surrounding structures. The inflammation may arise on its own or reflect something happening elsewhere in the body. Owners most commonly notice discharge from the vulva, which may be clear, cloudy, yellow, or streaked with blood. Some animals lick at the area more than usual, and the skin around the vulva may appear red or swollen. In many cases, the animal otherwise seems well, and the signs are subtle enough to be noticed only during grooming or rest. In an unspayed bitch, discharge from about two to sixteen weeks after a season, especially pus-like discharge or discharge with dullness, poor appetite, drinking more, vomiting or a swollen belly, also fits pyometra, an infection of the womb that can become life-threatening. The two cannot be told apart at home, and a closed pyometra may produce no discharge at all. This page explores what vaginitis can look like when it first appears, what may be happening beneath the surface, how the picture is built through examination and testing, and the range of approaches that exist depending on the underlying pattern. The goal is to help you understand the landscape, not to direct a particular course.
Vasculitis
Vasculitis describes inflammation of blood vessels, the network of tubes that carry blood throughout the body. When vessel walls become inflamed, they can leak fluid, weaken, or narrow, affecting the tissues those vessels supply. The condition can involve vessels of any size, from the smallest capillaries in the skin to larger vessels deeper in the body, and the signs often reflect which vessels are affected. Owners most commonly notice skin changes: patches of redness, bruising, ulcers, or crusting, particularly on the ears, paws, tail tip, or other areas where skin is thinner or more exposed. Some animals develop swelling in the legs, or small raised spots that may feel firm or tender. In other cases, the first signs are less visible (lethargy, joint discomfort or changes in appetite) because vessels in internal organs or tissues are involved. The pattern and severity vary widely, and the same outward signs can arise from many different underlying causes. This page explores what signals may point towards vasculitis, what processes can trigger inflammation in vessel walls, how the condition is investigated through examination and testing, and what approaches exist for managing it. The goal is to help you understand what vasculitis means in veterinary medicine and what shape the conversation with your vet may take.
Longevity & Healthspan
Adrenal Tumours
The adrenal glands sit near the kidneys and produce hormones that regulate metabolism, blood pressure, and the body's response to stress. A tumour in one of these glands can alter the normal pattern of hormone production, leading to a range of changes that usually unfold gradually over weeks or months, although a tumour that bleeds can cause sudden collapse. In dogs, the most common scenario involves excess cortisol, which can produce a distinctive picture: increased thirst and urination, a pot-bellied appearance, thinning skin, and changes in coat quality. In cats, adrenal tumours are less common and may be discovered incidentally or in the context of hormone imbalances. Many owners arrive at this page having noticed a slow accumulation of signs, perhaps a dog drinking more than usual, or a coat that no longer grows back after clipping. Others may have had a mass detected during imaging for an unrelated concern. The tumour itself may be benign or malignant, and it may or may not be actively secreting hormones; that distinction shapes both the picture the owner sees and the approach to investigation. This page explores what adrenal tumours can look like in practice, the mechanisms that connect gland changes to observable signs, how these tumours are identified and characterised, and the range of approaches (from monitoring to surgery to medical management) that exist depending on the tumour's behaviour, location, and the animal's overall picture.
Alimentary Lymphoma in Cats
Alimentary lymphoma is a cancer that arises from lymphocytes (white blood cells that normally help defend against infection) within the gastrointestinal tract. In cats, this is the most common anatomical form of lymphoma, and it develops when these cells begin to multiply uncontrollably in the lining of the stomach, small intestine, or large intestine. The behaviour of the disease can vary considerably depending on which type of lymphocyte is involved and how quickly the cells are dividing. Owners often notice gradual weight loss, reduced appetite, or occasional vomiting that does not resolve with simple measures. Some cats develop diarrhoea or appear less interested in food over weeks to months. Because these signs overlap with many other digestive conditions, the picture at home may be unclear for some time before a pattern becomes apparent. This page explores what signs may be observed, what is happening at a cellular level in the intestine, how the condition is investigated through imaging and tissue sampling, and what treatment approaches exist. The aim is to help you understand the nature of alimentary lymphoma and the shape of the conversations that may follow.
Anal Sac Adenocarcinoma
Anal sac adenocarcinoma is a cancer that arises from the glands that sit just inside the anus, in small pouches on either side of the anal opening. These glands normally produce scent-marking fluid, but cells within them can sometimes transform into a tumour that grows locally and has a tendency to spread to nearby lymph nodes and, later, to organs such as the liver, lungs or bone. Many owners first become aware of something unusual when they notice their dog scooting, licking around the rear, straining to pass faeces, or producing ribbon-shaped stools. In some cases a lump is felt during routine examination, or a blood test, sometimes prompted by increased thirst and urination, shows raised calcium. The tumour itself may remain small for a time, but spread to regional lymph nodes can occur early, sometimes before the primary mass is easily noticed. This page explores the signals an owner may observe, what is happening beneath the surface, how the condition is investigated through imaging and sampling, and the range of approaches that exist, including surgery, radiation, chemotherapy, and supportive care tailored to the individual dog's circumstances.
Basal Cell Tumours in Dogs and Cats
Basal cell tumours is a historical term for a group of skin growths that were once thought to arise from a single cell type, but are now understood to be distinct tumours with different origins. In dogs, most of what were called basal cell tumours are now classified as trichoblastomas. These are benign growths that develop from cells in the hair follicle. In cats, most are either trichoblastomas or apocrine ductular adenomas, which originate from sweat gland structures. The vast majority of these growths in both species are benign and behave in a quiet way once removed, though in cats a malignant form, basal cell carcinoma, can occur. Even this form usually stays in the skin, and spread to lymph nodes or other organs has been reported only rarely. Owners typically notice a small, firm, often hairless lump on the skin. In dogs it is most often on the head, neck or forelimbs, and in cats it can appear almost anywhere on the body. The lump may have been present for weeks or months and may grow slowly. In many cases, the growth is discovered during grooming or routine handling. There is often little else to observe: no pain, no discharge, no change in behaviour. This can make it difficult to know whether the lump warrants further attention. This page explores what these lumps can look like when they first appear, what is happening in the skin to produce them, how they are investigated and identified, and what approaches exist for managing them. The focus is on helping you understand the range of possibilities, the shape of the diagnostic process, and the factors that influence how these growths are handled once they are found.
Brain Tumours
A brain tumour is an abnormal growth of cells within the skull. It may arise from the brain tissue itself or the membranes around it, or spread from elsewhere in the body. These growths can press on surrounding structures, disrupt normal signalling, or alter the environment in which the brain works. Owners often arrive at this question after noticing changes that seem to come from the head: seizures that begin in an older animal, shifts in behaviour or personality, changes in balance or coordination, or patterns that suggest something affecting how the brain interprets or sends information. The signs can be subtle at first, or they can appear more suddenly, and they tend to reflect which part of the brain is involved. This page explores what these changes can look like when they first appear, the mechanisms by which tumours affect the brain, how the picture is built through imaging and other investigations, and the range of approaches (from monitoring to surgery, radiotherapy, and supportive care) that exist depending on the tumour, its location, and the individual animal.
Ceruminous Gland Tumours in Dogs and Cats
Ceruminous gland tumours are growths that arise from the wax-producing glands lining the ear canal. These glands normally produce a secretion that combines with sebum to form earwax; when cells in these glands begin to grow abnormally, they can form either benign tumours (adenomas) or malignant ones (adenocarcinomas). Whilst uncommon overall, ceruminous gland tumours are the most frequently encountered ear canal tumours in dogs, and one of the most common malignant ear tumours in cats. Malignant tumours are found more often than benign ones in both species. In one large study of ear canal tumours, about 6 in 10 dogs and nearly 9 in 10 cats had a malignant tumour. Some owners notice a mass inside the ear canal during grooming, but the tumour more often comes to light after signs such as head shaking, discharge or odour, and the mass is often seen only when the ear canal is examined with an otoscope. The growth may be visible as a pink, reddened, or ulcerated lump, and in some cases the ear canal can become narrowed or blocked. Chronic ear inflammation or recurrent infections can sometimes precede the appearance of a tumour, though the relationship between inflammation and tumour development remains an area of ongoing investigation. This page explores the signs that may bring a ceruminous gland tumour to attention, what is understood about how these tumours develop and behave, the investigations used to characterise them, and the range of approaches that exist for managing them. The distinction between benign and malignant forms, and the extent of local involvement, tends to shape the course and options available.
Chemodectoma (Heart Base Tumour)
A chemodectoma is a tumour that arises from specialised cells at the base of the heart, near the major blood vessels. These cells normally sense changes in blood chemistry, particularly oxygen levels. The tumour grows slowly and is typically found in older dogs, often during investigation of other concerns or as an incidental finding on imaging. Owners may notice no signs at all in the early stages. When signs do appear, they often relate to pressure on nearby structures or fluid accumulation around the heart: a dog may seem quieter, tire more easily, breathe with more effort, or develop a persistent cough, and when fluid compresses the heart a dog can weaken or collapse. Because the tumour sits in a complex area surrounded by vital structures, its behaviour depends largely on its size and position. This page explores the signals that can prompt investigation, what is happening within the chest, how these tumours are identified and monitored, and the range of approaches that exist. The tumour itself is rarely curable through removal, but understanding its pace and impact helps frame decisions about monitoring, managing fluid, and supporting quality of life over time.
Cholangiocarcinoma
Cholangiocarcinoma is a cancer that arises from the cells lining the bile ducts, the small tubes that carry bile from the liver to the intestine. It is uncommon in both dogs and cats, but when it does occur it tends to affect older animals. The tumour can develop within the liver itself or in the larger ducts outside the liver, and its behaviour varies with location and how far it has grown by the time it is found. Owners often notice signs that reflect disrupted bile flow or the space the tumour occupies: jaundice (a yellow tint to the gums, skin, or whites of the eyes), reduced appetite, weight loss, vomiting, or a quiet change in energy. Some animals show abdominal discomfort or a slightly distended belly. Because these signs overlap with many other liver and digestive conditions, the path to understanding what is happening typically involves blood tests, imaging, and sometimes sampling of tissue. This page explores what cholangiocarcinoma can look like in its early and later stages, what investigations help clarify the picture, how the tumour behaves over time, and what approaches exist when it is identified. The aim is to help you understand the condition, the questions that matter, and the shape of the road ahead.
Congestive Heart Failure in Dogs
Congestive heart failure describes what happens when the heart can no longer move blood efficiently enough to meet the body's needs, and fluid begins to accumulate in the lungs, chest cavity or abdomen as a result. It is not a disease in itself, but rather the end point of various heart conditions, such as valve disease, muscle disorders or rhythm disturbances, that have progressed to the stage where circulation becomes compromised. Many owners first notice a persistent cough, faster breathing at rest, or reduced stamina on walks. Some dogs become quieter, tire more easily, or seem reluctant to lie down flat. These signs tend to build gradually, though in some dogs fluid can build in the lungs over a matter of hours, producing laboured breathing at rest that cannot be relieved at home. A first episode of this kind is sometimes how previously unrecognised heart disease comes to light. The pattern often reflects which side of the heart is most affected, and how long the underlying condition has been developing. This page explores the signs that may be observed, the mechanisms that lead to fluid build-up, the tests used to assess heart function and guide decisions, and the range of approaches, medical and supportive, that exist to manage the condition over time. It does not tell you what your dog has, but it may help you understand what you are seeing and what questions may be worth exploring.
Cryptorchidism
Cryptorchidism describes the condition in which one or both testicles fail to descend fully into the scrotum. In dogs, the testicles normally move from their position near the kidneys down through the inguinal canal and into the scrotum during early development. When one testicle remains undescended, the condition is termed unilateral cryptorchidism; when both remain undescended, it is bilateral. Owners most commonly notice cryptorchidism when a puppy arrives for early vaccinations or neutering discussion, and the veterinary surgeon identifies that one or both testicles cannot be felt in the expected location. The retained testicle may be positioned in the abdomen or partway along the inguinal canal. Occasionally an owner may notice asymmetry in the scrotum, or a single firm structure where two would be expected. This page explores what can be observed on examination, the mechanisms underlying retained descent, how the condition is investigated when there is uncertainty, and the approaches taken to manage it over the animal's life. The discussion includes the implications for breeding, the differences between unilateral and bilateral presentations, and the factors that inform decisions about timing and method of surgical intervention.
Cutaneous Lymphoma
Cutaneous lymphoma is a condition in which a type of immune cell called a lymphocyte becomes cancerous and accumulates in the skin. These cells normally circulate through the body as part of the immune system, but in cutaneous lymphoma they multiply abnormally and gather in patches, nodules, or more widespread areas of the skin. It can occur in dogs and cats, though the appearance and behaviour of the condition differ between species. Owners most often notice raised lumps, thickened patches of skin, reddened areas, ulceration, or changes in pigmentation that may appear in one location or several. The signs can sometimes resemble other skin conditions such as infection, allergy, or benign growths, which is why the condition is often investigated over time. In some cases, changes elsewhere in the body may develop later, but the skin is the primary site of concern at the outset. This page explores what signs may be observed, what is happening at a cellular level, how the condition is investigated through biopsy and staging, and what treatment approaches exist. The aim is to orient you to the shape of the condition and the decisions that may unfold over time.
Dilated Cardiomyopathy in Dogs
Dilated cardiomyopathy is a condition in which the heart muscle becomes progressively weaker and the main pumping chambers enlarge. As the walls of the heart stretch and thin, the muscle loses its ability to contract forcefully, and blood begins to move less efficiently through the circulation. Over time, this can lead to fluid accumulating in the lungs or abdomen, and to episodes of collapse or sudden death from rhythm disturbances. Owners often arrive at this page because their dog has started coughing, breathing more rapidly at rest, tiring unusually quickly on walks, or has had an episode of weakness or collapse. Some dogs are investigated after a murmur or irregular heartbeat is heard during routine examination, before any outward signs appear. In certain breeds, including Dobermanns, Irish Wolfhounds, and Great Danes, the condition can progress silently for months or years. This page explores what may be observed at different stages, the mechanisms that drive the disease, how it is investigated using imaging and rhythm monitoring, and the medical approaches used to manage fluid overload, support heart function, and address arrhythmias. It does not diagnose an individual animal, but offers a framework for understanding what dilated cardiomyopathy is and how it tends to unfold.
Fibrosarcoma in Dogs
A fibrosarcoma is a type of tumour that develops from connective tissue cells called fibroblasts, which are found throughout the body. In dogs, these growths tend to appear in the skin or tissues just beneath it, mostly on the trunk and limbs. The mouth is another recognised site: fibrosarcoma is the third most common oral tumour in dogs, usually appearing as a firm, flat swelling on the gum. They are typically firm masses that grow slowly at first, though the rate and behaviour can vary considerably between individual cases. Owners often first notice a lump under the skin, sometimes while grooming or stroking the dog. The mass may feel solid and attached to surrounding tissue rather than freely movable. In many cases, there are no other signs at the time of discovery, which can make it difficult to judge the nature of the lump without further investigation. This page explores the patterns that may prompt investigation for fibrosarcoma, what is understood about how these tumours develop and behave, the ways they are identified and characterised, and the range of approaches used in their management. Because the term covers a spectrum of tumour behaviour, the information presented here reflects that variability rather than a single predictable course.
Gastric Adenocarcinoma
Gastric adenocarcinoma is a type of cancer that arises from the glandular cells lining the stomach. These cells normally produce mucus and digestive fluids, but when they become cancerous, they can form masses or thicken the stomach wall in ways that interfere with normal digestion and movement of food. It occurs most commonly in older dogs, with certain breeds appearing more susceptible, and is rare in cats. Owners often arrive at this page because their dog or cat has been vomiting intermittently, losing weight despite a reasonable appetite, or showing a gradual decline in energy and interest in food. These signs can develop slowly over weeks or months, and may initially be mistaken for less serious digestive upset. In some cases, the condition is discovered during investigation of anaemia or abdominal discomfort. This page explores the signals that may prompt investigation, what is happening at a tissue and cellular level, how the condition is identified through imaging and biopsy, and the range of approaches that exist (surgery, chemotherapy and supportive care), each with its own considerations and limitations.
Geriatric Frailty in Dogs
Geriatric frailty describes a state in which an older dog's ability to respond to physical stress becomes noticeably reduced. It reflects a gradual decline across multiple body systems rather than one specific illness, and tends to show itself through a cluster of changes: reduced muscle mass, slower recovery from minor setbacks, less tolerance for cold or heat, and a narrower margin for error when something goes wrong. Owners often arrive at this page because they have noticed their dog tiring more easily, struggling to bounce back from a routine vaccine reaction or a mild stomach upset, or simply seeming more fragile than they were a year ago. The changes can be subtle at first, and it can be difficult to know which signs reflect normal ageing and which suggest something that warrants closer attention. This page explores the patterns that characterise frailty, what is happening in the body when resilience begins to narrow, how frailty is assessed in practice, and the range of approaches that can support quality of life and help maintain function for as long as possible.
Glioma in Dogs
A glioma is a tumour that arises from the supporting cells inside the brain itself: the glial cells that surround and insulate nerve tissue. These tumours grow within the substance of the brain, rather than on its surface or in surrounding structures, and their behaviour varies: some are low-grade and slow-growing, but the most common form in dogs is high-grade and progresses more rapidly. Owners often arrive on this page because their dog has developed changes in behaviour, coordination, or awareness that have persisted or worsened: perhaps seizures that have begun in an older dog, a head tilt or circling that does not resolve, or subtle shifts in personality or responsiveness. These signs reflect disruption to specific regions of the brain, and the pattern depends on where the tumour is located and how quickly it is expanding. This page explores what those early signals can look like, what is happening beneath them, how gliomas are investigated using imaging and sometimes biopsy, and what approaches exist, from monitoring and supportive care to surgery, radiation, and chemotherapy. The aim is to help you understand the landscape, not to prescribe a path.
Haemangiosarcoma
Haemangiosarcoma is a cancer that arises from the cells lining blood vessels. It tends to form tumours that are fragile and prone to bleeding, and it can develop in many parts of the body, most often the spleen, heart or skin, and less often the liver. Because the tumours are blood-filled and can rupture without warning, the first sign may be sudden collapse, weakness, or pale gums, rather than a gradual decline. Many owners arrive on this page after their dog has experienced an unexplained episode of weakness or collapse, or after a mass has been found on imaging or during an examination for something else. The condition can also present as a visible lump on the skin, particularly in areas exposed to sunlight. The internal form is more common in older dogs, and certain breeds, including Golden Retrievers, German Shepherds, and Labrador Retrievers, are seen more frequently. This page explores what an owner may observe, what is happening inside the body, how haemangiosarcoma is investigated and confirmed, and the range of approaches that exist once a diagnosis is made. It also considers the factors that shape outlook and the conversations that often follow.
Hepatocellular Carcinoma
Hepatocellular carcinoma is a type of cancer that originates in the liver cells themselves. It tends to develop as a single large mass within the liver, though sometimes multiple nodules form. This is distinct from cancers that spread to the liver from elsewhere in the body. Many dogs with hepatocellular carcinoma show no signs at all in the early stages, and a mass may be discovered incidentally during imaging for another reason or during routine health screening in older animals. When signs do appear, they are often vague: reduced appetite, weight loss, occasional vomiting, or a general sense that the dog is not quite right. Because the liver has significant reserve capacity, signs may not emerge until the tumour is quite large. In cats, this tumour is much less common. This page explores the signals that may prompt investigation, what is happening at a cellular level, how hepatocellular carcinoma is identified and staged, and the range of approaches that may be considered depending on the tumour's size, location, and whether it has spread beyond the liver.
Histiocytic Sarcoma in Bernese Mountain Dogs
Histiocytic sarcoma is a cancer that arises from a type of immune cell called a histiocyte. These cells normally move through tissues as part of the body's surveillance system, but in this condition they begin to multiply without the usual constraints. In Bernese Mountain Dogs, this cancer occurs more commonly than in most other breeds, reflecting an inherited susceptibility that researchers continue to study. Owners often first notice signs that can seem vague or unconnected: reduced appetite, weight loss, lethargy, difficulty breathing, limping, or swelling in a limb or under the skin. Because the disease can start in different parts of the body (lung, spleen, bone, lymph nodes, skin, or brain), the early picture varies. One form arises in the spleen and bone marrow together and tends to show itself through its effect on the blood (paleness, weakness, and lethargy from anaemia) rather than through an obvious lump, and this form in particular tends to progress over a small number of weeks. In the widespread (disseminated) form, seen in about six in ten affected Bernese Mountain Dogs in one large study, the course is usually measured in weeks to months. A single localised tumour treated with surgery and chemotherapy has been reported in a small study with a median survival of more than a year. This page explores what signs may be observed and when they tend to develop, what is happening in the body at a cellular level, how the condition is investigated through imaging and laboratory tests, and what treatment and supportive approaches exist. The goal is to help you understand the nature of the condition and the shape of the decisions that may follow.
Histiocytoma
A histiocytoma is a small, benign growth that arises from a type of immune cell in the skin. It is one of the more common skin lumps seen in young dogs, typically appearing as a single, firm, dome-shaped nodule that can be pink, red, or ulcerated on the surface. Most owners notice it suddenly, and many are concerned by how quickly it appears or by its raw appearance. These growths are not cancerous and tend to resolve on their own over a period of weeks to months, though their behaviour can vary. The pattern of growth, regression, and occasional persistence shapes how they are approached. This page explores what signs may prompt attention, what is happening in the tissue, how histiocytomas are identified and distinguished from other lumps, and the range of approaches that exist when observation, biopsy, or removal may be considered.
Hypertrophic Cardiomyopathy in Cats
A condition where the heart muscle thickens abnormally, impairing blood flow and potentially causing sudden circulatory complications.
Injection-Site Sarcoma in Cats
An injection-site sarcoma is a type of tumour that can develop in cats at locations where injections have been given in the past. These growths arise from the soft tissue beneath the skin and tend to grow locally, often with irregular borders that make complete removal challenging. The link between certain vaccines or injectable medications and these tumours was recognised in the 1990s, though they remain uncommon overall. Owners typically notice a firm lump or swelling under the skin, often between the shoulder blades, along the back, or in the hind leg, areas where vaccines and other injections are commonly given. The lump may appear weeks, months, or even years after an injection. Not every lump at an injection site is a sarcoma; many are benign reactions that resolve on their own, but lumps that persist beyond the expected healing window or keep growing tend to prompt further investigation. This page explores what changes may signal concern, what is understood about how these tumours develop, how they are investigated through imaging and biopsy, and the range of approaches available (surgery, radiation and chemotherapy), each with its own scope and trade-offs.
Insulinoma
Insulinoma is a tumour of the pancreas that produces excessive insulin, the hormone that lowers blood glucose. In dogs, these tumours are nearly always malignant, and metastatic spread to lymph nodes or liver is common at the time of diagnosis. The excess insulin causes episodes of low blood sugar, which can affect the brain and nervous system and, when severe and prolonged, can lead to lasting brain injury, coma and death. Owners often notice intermittent signs: sudden weakness, confusion, wobbliness, trembling, or collapse that resolve on their own or after eating. The pattern tends to be episodic because signs appear when glucose use rises or supply falls. Signs may occur hours after a meal, during exercise or excitement, soon after eating, or with no obvious trigger. This page explores what low blood sugar can look like in day-to-day life, how the diagnosis is made, the role of imaging in understanding spread, and the approaches available (including surgery, dietary strategies, and medication) alongside what each may and may not achieve.
Intestinal Adenocarcinoma
Intestinal adenocarcinoma is a cancer arising from the glandular cells that line the small or large intestine. These cells normally produce mucus and help with absorption; when they become cancerous, they form tumours that can narrow the bowel, bleed, or interfere with normal digestion and movement of food through the gut. Owners often first notice weight loss, changes in appetite, vomiting, or diarrhoea that may be intermittent at first and then become more persistent. Some dogs or cats may pass dark or tarry stools if there is bleeding from the tumour. Because these signs can overlap with many other digestive conditions, the underlying cause may not be clear until investigations are carried out. This page explores the patterns that may prompt investigation, what happens at a tissue level when this cancer develops, how it is identified through imaging and biopsy, and the range of approaches that exist, including surgery, chemotherapy, and supportive care. The goal is to help you understand the condition and the framework within which decisions are made.
Lipomas
A lipoma is a benign growth made of fat cells that develops under the skin. These soft, moveable lumps are among the most common masses found in dogs, particularly as they grow older, and they occur occasionally in cats as well. They do not spread to other parts of the body and typically grow slowly over months or years. Most owners first notice a lipoma as a soft lump beneath the skin that moves easily when touched. The lump may appear on the chest, belly, or limbs, though it can develop almost anywhere. Many dogs live comfortably with one or several lipomas that never require treatment, though some masses can grow large enough to affect movement or quality of life depending on where they sit. This page explores what lipomas look like and feel like, how they differ from other kinds of lumps, the ways they can be investigated, and the approaches that exist when a lipoma becomes problematic. It also considers when observation alone may be appropriate and when further steps might be worth discussing.
Mammary Adenocarcinoma in Cats
Mammary adenocarcinoma is a malignant tumour that arises from the glandular tissue of the mammary glands. In cats, 80 to 90% of mammary tumours are malignant. They tend to behave more aggressively than similar growths in dogs, and they can spread to other parts of the body, including the lungs and lymph nodes. The tissue involved is the same tissue that produces milk, though these tumours can appear in neutered and intact females, and occasionally in males. Owners often first notice a lump or firm mass along the mammary chain (the paired rows of glands that run along the underside of the chest and abdomen). These lumps may grow quickly or slowly, may be single or multiple, and may feel fixed or mobile beneath the skin. Some cats show no other signs at first, whilst others may develop ulceration of the overlying skin, or changes in appetite, breathing, or energy if the disease has spread. This page explores the signals that may prompt an owner's attention, the biological processes that underlie mammary tumours in cats, the investigations used to characterise them, and the range of approaches that exist for managing this condition. The aim is to orient, not to advise, and to provide a framework for understanding what may be observed.
Mast Cell Tumours
Mast cell tumours are growths that arise from mast cells, immune cells normally involved in allergic responses and wound healing. In dogs they are among the most commonly diagnosed skin tumours, while in cats they are less frequent but tend to behave differently. They can appear as a single lump or nodule anywhere on the body, often on the trunk or limbs, and may look like almost anything: a small raised bump, a flat patch, a red swollen area, or a growth that changes size from day to day. Owners often notice a lump during grooming or after a minor knock, and the tumour may appear to fluctuate in size or become inflamed. Some mast cell tumours remain stable for months or years, while others grow quickly or ulcerate. The behaviour of an individual tumour can vary widely, and the appearance alone does not reliably indicate how it will act. This page explores what mast cell tumours may look like when first noticed, what is happening within the tissue, how they are investigated and graded, and the range of approaches used depending on location, grade, and the individual animal. The aim is to orient you to the possibilities, the questions that may arise, and the shape of the decisions that can follow.
Mast Cell Tumours in Cats
Mast cell tumours are growths that arise from mast cells, a type of immune cell normally found in skin and other tissues. In cats, these tumours most often appear as single or multiple skin nodules or lumps, though they can also develop in internal organs, particularly the spleen and intestines. The appearance and behaviour vary considerably: some remain small and cause no trouble, whilst others grow, spread, or release chemicals that affect surrounding tissues. Owners often discover a new lump during grooming, or notice a bump that has changed in size or texture. Because mast cell tumours in cats can look similar to many other skin growths, and because their behaviour ranges from entirely benign to more concerning, sampling the lump, usually first with a fine needle, is typically needed to understand what is present. The tumour's location, appearance under the microscope, and certain laboratory markers help clarify what to expect. This page explores what mast cell tumours look like when they first appear, what drives their development, how they are investigated and graded, and the range of approaches used to manage them. The goal is to provide a clear picture of what this diagnosis can mean and what questions may be useful to explore.
Mast Cell Tumours in Dogs
A mast cell tumour is a growth that arises from mast cells, immune cells that normally live in the skin and other tissues, where they play a role in allergic responses and inflammation. In dogs, these tumours can appear as lumps or bumps on the skin, and they vary widely in how they look and how they behave. Some remain small and cause little trouble; others grow quickly, spread to other parts of the body, or release chemicals that cause signs elsewhere. Many owners notice a new lump during grooming, or find that an existing bump has changed in size, colour, or texture. Mast cell tumours can mimic benign growths, which is why a lump that looks unremarkable on the surface may still warrant closer attention. Some tumours ulcerate, itch, or swell intermittently, particularly if they are disturbed. This page explores what mast cell tumours can look like when they first appear, what drives their behaviour, how they are investigated and graded, and the range of approaches used to manage them, from surgery and radiation to drug therapy. The goal is to help you understand the landscape, not to predict what will happen in any individual case.
Meningioma
A meningioma is a growth that arises from the meninges, the protective membranes that surround the brain and spinal cord. In dogs and cats, these growths develop most often around the brain, and although they tend to grow slowly and rarely spread to other parts of the body, they can still cause problems by pressing on nearby brain tissue as they enlarge. Owners most commonly notice changes in behaviour, unexplained seizures that begin in an older animal, subtle shifts in personality, or signs such as unsteadiness, head pressing, or changes in vision. The signs depend on where the growth is located and how much pressure it exerts. Some meningiomas, particularly in cats, are found by chance during imaging or other tests performed for another reason, before any outward signs appear. This page explores what signals may bring a meningioma to attention, what is happening beneath the surface, how these growths are investigated using imaging and sometimes biopsy, and the range of approaches (including monitoring, surgery and radiation) that may be considered depending on location, size, and the individual animal's circumstances.
Mitral Valve Disease in Dogs
Mitral valve disease is a progressive change in the valve that sits between the left atrium and left ventricle of the heart. The valve leaflets thicken and lose their ability to seal properly, allowing blood to leak backwards with each heartbeat. This is one of the most common heart conditions seen in older dogs, particularly in smaller breeds. Many owners first become aware of mitral valve disease when a heart murmur is detected during a routine examination, often before the dog shows any outward signs. As the condition progresses, some dogs develop a cough, tire more easily during walks, or breathe more rapidly at rest. Others may live for years with valve changes that remain mild and cause no noticeable disruption. This page explores what mitral valve disease looks like across its spectrum, the signs that can develop as the heart adapts to the leaking valve, how the condition is monitored over time, and the range of approaches used to support dogs at different stages. The course is variable: it is generally slow, but at times it changes quickly and unpredictably.
Multicentric Lymphoma in Dogs
Multicentric lymphoma is a condition in which lymphocytes (white blood cells that normally patrol the body as part of the immune system) begin to multiply in an uncontrolled way within the lymph nodes. These nodes, which sit at junctions throughout the body, become visibly enlarged. In dogs, this form of lymphoma tends to affect multiple node groups at once, which is why it carries the name multicentric. Owners often first notice firm, painless swellings under the jaw, in front of the shoulders, or behind the knees. The dog may otherwise seem well in the early stages, or there may be quieter signs such as reduced appetite, weight loss, or a general sense that energy has dipped. Because the nodes themselves are not usually tender, the swelling can be present for some time before it prompts concern. This page explores what these swellings may signal, what is happening within the lymphatic system, how the condition is investigated through examination and laboratory work, and the range of approaches that exist once a picture has formed. The goal is orientation, not instruction: understanding the landscape so that conversations with the veterinary team can be as clear and grounded as possible.
Multiple Myeloma
Multiple myeloma is a condition in which a type of white blood cell called a plasma cell begins to multiply abnormally in the bone marrow. These cells can crowd out healthy blood cells and produce abnormal proteins that circulate in the blood and may be filtered into the urine. The condition tends to affect older dogs more commonly than cats, and it develops gradually. Owners often notice signs that can seem unrelated at first: lethargy, weakness, increased thirst, or lameness that may come and go. Some dogs develop nosebleeds or bruise more easily. In other cases, the condition is detected through routine blood work before any outward signs appear. The variety of possible presentations reflects the different ways these abnormal cells and their proteins can affect the body. This page explores what signs may prompt investigation, the mechanisms by which plasma cells behave this way, how the condition is identified through blood tests and imaging, and the range of approaches that exist to manage it. The course and outlook vary considerably between individuals.
Nerve Sheath Tumour
A nerve sheath tumour is a growth that arises from the cells that wrap around and support peripheral nerves, the nerves outside the brain and spinal cord that carry signals to and from the limbs, face, and body. These tumours can develop anywhere a peripheral nerve runs, and they tend to grow slowly over weeks to months. In dogs, they occur most often in middle-aged to older animals, and certain larger breeds may be more commonly affected. In dogs, most of these tumours arise in the brachial plexus (the nerve network in the armpit that serves the front leg) or in the nerve roots beside the spine, where a lump can rarely be felt. Owners more often first notice the dog favouring a front leg, showing discomfort when moving, or weakness or altered sensation in a specific area. A firm lump under the skin is more typical of tumours arising from nerves in the skin. Because the tumour involves a nerve, signs can include lameness that does not improve with rest, muscle wasting in the affected limb, or changes in how the paw is placed or held. In some cases, a tumour affecting a nerve in the chest or abdomen may cause signs that are less easy to localise. This page explores the signals that may suggest a nerve sheath tumour, what is happening at the level of the nerve and surrounding tissue, how these growths are investigated through imaging and sampling, and the range of approaches that exist for managing them. The goal is to help you understand the nature of the condition and the framework within which decisions are made.
Nuclear Sclerosis
Nuclear sclerosis is a gradual change in the lens of the eye that occurs as dogs age. The lens fibres at the centre become more densely packed over time, which can give the pupil a hazy, blue-grey appearance when light catches it at certain angles. This is a normal part of ageing, not a disease, and it does not cause blindness. Many owners first notice it when their older dog's eyes look cloudy, and wonder whether their dog is developing cataracts or losing vision. The appearance can be subtle or quite pronounced, and it tends to progress slowly over years. Dogs with nuclear sclerosis typically navigate their environment without difficulty, though fine detail may be seen less clearly, and denser changes are linked with mild visual deficits in some dogs. This page explores what owners may observe, the structural changes occurring within the lens, how nuclear sclerosis is distinguished from other causes of cloudiness, and the ways it may or may not affect day-to-day function as dogs age.
Oral Melanoma
Oral melanoma is a cancer that arises from pigment-producing cells in the mouth. In dogs, it tends to appear as a dark mass on the gums, roof of the mouth, or tongue, though not all oral melanomas are visibly pigmented. Owners often first notice a lump during routine tooth-brushing, a change in the shape of the gumline, or sometimes bleeding or difficulty eating. This is a cancer that can behave aggressively in dogs, with a tendency to invade local bone and spread to lymph nodes and lungs, though the speed and pattern vary between individuals. In cats, oral melanoma is very rare, and the small published case series describe short survival times. This page explores what signs may be observed, what is happening at a tissue level, how oral melanoma is investigated and staged, and what treatment approaches exist. It does not diagnose any individual animal, but offers a framework for understanding what this diagnosis can mean.
Oral Squamous Cell Carcinoma in Cats
Oral squamous cell carcinoma is a type of cancer that arises from the flat cells lining the mouth. In cats, these tumours tend to grow locally within the tissues of the gums, tongue, tonsils or other structures in the oral cavity. They are locally invasive, often affecting bone, and the outlook is generally poor. They may cause visible changes in the mouth along with difficulty eating or other signs that prompt closer investigation. Owners often notice reluctance to eat, drooling, a visible mass or swelling in the mouth, bad breath, or bleeding. Sometimes the first sign is a loose tooth or facial asymmetry. The changes may develop gradually, and early appearances can be subtle or mistaken for dental disease. Weight loss may follow if eating becomes uncomfortable. This page explores what signs may be seen, what is happening in the tissues, how the condition is investigated through examination and diagnostics, and what approaches exist for managing it. The aim is to help you understand the nature of oral squamous cell carcinoma in cats and the shape of the decisions that may follow diagnosis.
Osteosarcoma
Osteosarcoma represents an aggressive bone cancer most commonly affecting the limbs of large and giant breed dogs, often presenting with progressive lameness.
Osteosarcoma in Dogs
Osteosarcoma is a cancer that begins in bone-forming cells, most often affecting the long bones of the legs in middle-aged to older dogs. It tends to grow quickly within the bone itself, causing pain and weakening the structure until fractures can occur with minimal force. Large and giant breeds are disproportionately affected, though the condition can appear in dogs of any size. Many owners first notice a subtle lameness that worsens over days to weeks, or they may feel a firm swelling over a limb. Because the early signs can resemble an injury or arthritis, the pattern often becomes clearer only as the discomfort persists or a limb becomes visibly enlarged. In some cases, a fracture through weakened bone is the first obvious sign. This page explores what osteosarcoma can look like in its early and later stages, what is happening inside the bone and elsewhere in the body, how the condition is investigated through imaging and sampling, and the range of surgical, medical and supportive approaches that exist for managing it. The course and options vary considerably between individual dogs, shaped by factors including tumour location, spread, age, and temperament.
Periodontal Disease
Periodontal disease describes the progressive damage to the structures that hold teeth in place: the gums, the ligament that anchors each tooth, and the bone of the jaw itself. It begins with plaque, a soft film of bacteria that re-forms on a cleaned tooth surface within about a day. If plaque is not removed, it mineralises into tartar, and the bacteria beneath trigger inflammation that can eventually erode bone and loosen teeth. Many owners first notice a change in breath odour, reluctance to eat hard food, or a visible brown crust along the gum line. Some dogs and cats show no outward sign at all, even when disease beneath the gum is well established. The condition is extremely common, with most dogs and cats showing some degree of periodontal change by two years of age, but the rate of progression and the severity vary widely between individuals. This page explores what periodontal disease looks like from the outside, what is happening beneath the gum line, how the extent of damage is assessed, and the range of approaches used to slow progression or manage established disease. It also covers the role of home care, professional cleaning under anaesthesia, and the products that have been evaluated by the Veterinary Oral Health Council for their effect on plaque and tartar.
Phaeochromocytoma in Dogs
A phaeochromocytoma is a tumour that develops in specialised tissue inside the adrenal gland, a small organ that sits near the kidney and produces hormones involved in stress response and blood pressure regulation. These tumours can release surges of adrenaline and related hormones into the bloodstream, sometimes unpredictably, which may create episodes of rapid heart rate, restlessness, heavy breathing, or collapse. In other cases, the release is steadier and signs develop more gradually. Owners often arrive at this possibility after observing intermittent episodes that seem out of character (panting without obvious cause, sudden weakness, or behaviour that suggests anxiety or discomfort), sometimes with normal periods in between. The episodes can vary in intensity and frequency, and in some dogs the condition is discovered incidentally during imaging or investigation for another concern. This page explores the signs that may prompt consideration of a phaeochromocytoma, what is happening inside the adrenal gland and the wider body, how the condition is investigated through blood tests and imaging, and the approaches that exist for managing it, including surgery and medical options. The course and outcome depend on factors including the size and behaviour of the tumour, whether it has spread, and the individual dog's response to treatment.
Pituitary Macroadenoma
A pituitary macroadenoma is a relatively large, typically benign growth in the pituitary gland, a small structure at the base of the brain that produces hormones influencing metabolism, growth, and reproduction. The term 'macro' is conventionally applied to a pituitary tumour 10 mm or more across. Enlargement is also judged in relation to the size of the brain, using the pituitary's height relative to brain area (the P:B ratio, with values above 0.31 indicating an enlarged gland). Such tumours may exert physical pressure on surrounding brain tissue as well as disrupt normal hormone production. This can lead to effects both from excess hormone release and from compression of nearby structures. In dogs, owners often become aware of the possibility through changes in drinking and urination, appetite, energy, or behaviour, or because investigations for another concern have revealed an abnormality on blood tests or imaging. When the growth itself causes signs, the most common are vague ones: dullness, lethargy and a reduced appetite or refusal of food. Circling, seizures and loss of vision occur, but less often. In cats, the most common functional pituitary tumour instead produces excess growth hormone (acromegaly), which typically comes to light as diabetes that needs unusually high insulin doses. The presentation depends on which hormones are affected, how large the growth has become, and which adjacent structures are influenced. This page explores the signals that may be observed, the mechanisms underlying those signals, the investigations used to characterise the growth and its effects, and the range of approaches that exist, from monitoring and hormone management to radiation and surgery. Each section is written to help you understand what may be happening and what conversations may follow.
Plasmacytoma
A plasmacytoma is a tumour that arises from plasma cells, the specialised white blood cells responsible for producing antibodies. These tumours can develop in the skin, in the mouth or throat, or less commonly in other locations. In dogs, they tend to occur in older animals and are most often found as solitary growths rather than part of widespread disease. Owners typically notice a raised lump on the skin, often on a paw, ear, or lip, or a growth inside the mouth that may bleed, interfere with eating, or simply be visible during routine care. The appearance alone does not reveal whether the growth is a plasmacytoma or another type of tumour, and many owners arrive at this page after a biopsy has been discussed or completed. This page explores what plasmacytomas can look like when they first appear, what investigations help clarify the diagnosis and extent, the biological behaviour of these tumours in different locations, and the range of approaches used to manage them. The aim is to set out the range of possibilities, not to predict what will happen in any individual case.
Renal Lymphoma in Cats
Renal lymphoma is a cancer of white blood cells that infiltrates the kidneys, usually both of them. The malignant cells crowd into the kidney tissue, often causing the kidneys to enlarge and lose their ability to filter waste from the blood. Cats with this condition tend to show signs of kidney dysfunction (reduced appetite, weight loss, increased thirst and changes in urination), and these signs can develop quickly or unfold over weeks. Most affected cats are middle-aged or older, and males are over-represented. Since widespread introduction of FeLV vaccination, the median age of affected cats has increased and most cases are now not associated with feline leukaemia virus infection. This page explores what renal lymphoma can look like in daily life, what is happening inside the kidneys, how the condition is investigated through imaging and sampling, and what approaches exist for managing it.
Sarcopenia in Senior Dogs
Sarcopenia is the progressive loss of muscle mass and strength that occurs as dogs age. It reflects changes in how muscle tissue is built, maintained, and broken down over time, and tends to accelerate in the senior and geriatric years. The process is distinct from simple disuse: it involves shifts in metabolism, hormone signalling, inflammation, and the way the body responds to nutrition and activity. Owners often notice that an older dog feels lighter when lifted, moves more slowly on walks, or struggles with stairs or jumping into the car, changes that can look very similar to those caused by joint pain, which is common in older dogs and often not obvious. Some dogs appear thinner over the hips and spine, or tire more quickly during familiar routines. These changes can develop gradually, and age-related muscle loss often cannot be told apart at home from muscle loss caused by osteoarthritis pain, spinal or nerve disease, or an underlying illness. Muscle loss that develops over weeks, affects one side more than the other, or comes with weight loss, reduced appetite, increased thirst, or scuffing or knuckling of the hind feet does not fit ageing alone. This page explores the signals that may suggest sarcopenia, the biological processes that drive muscle loss in older dogs, how the condition is assessed in practice, and the range of approaches that can be considered to support muscle health and function in the senior years.
Sebaceous Cysts
A sebaceous cyst is a small, enclosed pocket that forms in or just beneath the skin, filled with keratin and sometimes oily material. These lumps are typically benign and slow-growing. They are common in dogs, and a dog that develops one is prone to developing more over time. The term is often used broadly to describe several types of skin cysts, though in veterinary medicine the most common are actually epidermoid cysts or follicular cysts, which have slightly different origins but behave similarly. Owners most often notice a firm, round lump under the skin that may remain the same size for months or years, or gradually enlarge. The cyst may feel movable, and occasionally a small pore or opening can be seen on the surface. Some cysts rupture spontaneously, releasing a thick, paste-like substance that can have a distinctive odour, which may prompt concern about infection or something more serious. This page explores what these lumps typically look like and feel like, what is happening beneath the surface, how they are distinguished from other skin masses, and the range of approaches that exist for managing them, including when observation alone may be appropriate and when removal might be considered.
Sensory Decline in Senior Pets
As dogs and cats age, their senses (sight, hearing, smell, taste and touch) can gradually become less sharp. This is a normal part of ageing in many animals, though the pace and pattern vary widely. Some pets experience barely noticeable changes; others lose significant function in one or more senses over months or years. Owners often notice that their pet startles more easily, seems less interested in food, bumps into furniture in dim light, or no longer responds to their name from across the room. Age-related changes usually build up slowly, although owners often notice them all at once. Sight lost over hours or days, or a red, painful eye, points to other conditions that cannot be judged at home, as set out below. It can be difficult to tell whether a gradual change reflects sensory decline, another medical condition, or simply a shift in behaviour or attention. This page explores the signals that may suggest sensory decline, the processes that underlie these changes, how veterinary surgeons investigate them, and the range of approaches that exist to support affected animals. The goal is to help you understand what may be happening and what shape the conversation with your practice might take.
Soft Tissue Sarcomas
Soft tissue sarcomas are a family of tumours that arise from the connective tissues beneath the skin: the structures that support, cushion and bind the body together. They can develop from fat, muscle, the sheaths around nerves, blood vessel walls or the fibrous tissue that separates organs. Most are noticed as a lump under the skin, often on a limb or the body wall, that may have been present for weeks or months before growing noticeably. These tumours tend to grow locally, expanding into surrounding tissue rather than spreading to other organs, particularly when low grade. The lump may feel firm or soft, fixed or mobile, and size alone does not reliably indicate behaviour. Many owners arrive here wondering whether a lump that has appeared or changed is something to monitor, investigate or address, and what the timeframe for that decision looks like. This page explores what soft tissue sarcomas look like when they first appear, the signals that prompt investigation, how they are identified and assessed, and the range of approaches used to manage them. It also considers factors that influence outcome, including tumour type, location and grade, and what follow-up typically involves.
Splenic Lymphoma
Splenic lymphoma is a form of cancer affecting the white blood cells within the spleen, the organ that filters blood and plays a role in immune function. The spleen becomes infiltrated with abnormal lymphocytes (cells that would normally help fight infection) and this can lead to enlargement, changes in blood counts, or disruption of the organ's normal work. Many dogs with splenic lymphoma show no outward signs at first, and the condition may be noticed during imaging or blood tests carried out for another reason. When signs do appear, they often include a quieter demeanour, reduced appetite, weight loss, or a sense that something has shifted in energy or routine. In some cases, the spleen becomes large enough to be felt during examination, or complications such as rupture or low platelet counts bring the condition to attention. This page explores the patterns that may signal splenic lymphoma, the mechanisms underlying the disease, the investigations used to characterise it, and the range of approaches that exist once a picture has formed.
Splenic Mass
A splenic mass is a lump or growth that develops in the spleen, an organ tucked beneath the ribcage on the left side of the abdomen. These masses can be discovered during routine imaging, after a period of vague unwellness, or sometimes when a dog collapses unexpectedly. They range from benign blood-filled nodules to more serious tumours, and the spleen's rich blood supply means that a mass can rupture and bleed into the abdomen with little warning. A large bleed causes collapse and can end in sudden death, and neither the amount of blood lost nor whether the bleeding has stopped can be judged from outside the dog. Many owners arrive at this page after an ultrasound or X-ray has shown something unusual, or because their dog has had an episode of weakness or pale gums that prompted investigation. The mass itself often causes no outward signs until it reaches a certain size or changes in some way. Because the spleen sits out of sight and performs quiet background work in filtering blood and storing red cells, changes within it tend to go unnoticed until imaging brings them to light. This page explores what signs may appear, what is happening inside the spleen when a mass forms, how these growths are investigated and characterised, and what approaches exist depending on the type and behaviour of the mass. The goal is to provide a framework for understanding what has been found and what questions may be worth exploring as the picture becomes clearer.
Squamous Cell Carcinoma
Squamous cell carcinoma is a cancer that arises from the flat, scale-like cells of the skin and of linings such as the mouth. This page covers the skin form in cats, which mostly affects lightly pigmented, sparsely haired skin exposed to sun: the ear tips, nose and eyelids. It tends to begin as a small, persistent change in one place and grow slowly and locally, often appearing as a thickened patch, a non-healing sore, or an area that bleeds easily. Squamous cell carcinoma inside the mouth of cats behaves far more aggressively, with a much poorer outlook, and is covered on its own page. Owners often notice a scab or crust on an ear tip that keeps returning, a raw area on the nose that does not heal, or redness and crusting at the eyelid edge. Early changes can be subtle and are easily mistaken for a fight wound, infection or minor injury. This page explores what an owner may observe, what is happening at the tissue level, how the diagnosis is confirmed, and the range of approaches that may be considered depending on the site, the extent of local involvement, and whether spread has occurred.
Squamous Cell Carcinoma in Cats
Squamous cell carcinoma in cats commonly affects sun-exposed areas like the ears and nose, particularly in white-coated individuals, developing from precancerous changes to invasive cancer. A separate form arises in the mouth, where it is the most common oral tumour in cats and carries a much poorer outlook.
Squamous Cell Carcinoma of the Nasal Planum
Squamous cell carcinoma of the nasal planum is a type of skin cancer that arises from the flat cells lining the surface of the nose leather, the hairless area at the tip of a dog's or cat's nose, which may be pigmented or pink. These tumours grow locally, often beginning as a small rough patch or persistent sore that does not heal, and over time can erode into the surrounding tissue. They tend to occur in older animals and are more common in those with lighter or unpigmented skin on the nose, particularly in cats. Owners often notice a change in the appearance of the nose itself: a crusted area, a raised or ulcerated lesion, occasional bleeding, or a gradual loss of the normal finely bumpy (cobblestone) texture. The lesion may be present for weeks or months before prompting concern, and it can be mistaken for an injury, infection, or allergic reaction at first. In cats, these changes are sometimes subtle and progress slowly. This page explores the signals that may raise suspicion, what is happening in the tissue beneath the surface, how the condition is investigated through biopsy and imaging, and the range of approaches (surgical, radiation-based, and supportive) that may be considered depending on the extent and location of the tumour.
Squamous Cell Carcinoma of the Pinna in Cats
Squamous cell carcinoma of the pinna is a form of skin cancer that arises in the thin, flat cells lining the surface of the ear flap. In cats, this tends to occur in areas where sun exposure has damaged the skin over time, particularly in animals with white or pale ears. The condition develops slowly, often beginning as persistent roughness, redness, or small crusted areas that may come and go before progressing to open sores or thickened patches that do not heal. Owners often notice changes that initially resemble minor injuries or irritation: small scabs, recurring scratches, or areas that bleed easily when touched. These signs may be present for weeks or months before the pattern becomes clear. Because the changes can be subtle at first, and because ear tips are naturally exposed and occasionally injured, it is not always obvious when something more persistent is unfolding. This page explores what squamous cell carcinoma of the pinna can look like in its early and later stages, what is happening in the skin as the condition develops, how veterinary surgeons investigate and confirm the diagnosis, and what approaches exist for managing it. The aim is to help orient you to the condition and the questions that may arise as you and your veterinary team work through what is happening.
Synovial Cell Sarcoma
Synovial cell sarcoma is a rare tumour that arises from the soft tissues around joints, tendons, and bursae: the structures that support movement and cushion bone surfaces. It tends to grow locally and can, in some cases, spread to other parts of the body. The condition is uncommon in dogs and exceptionally rare in cats. Owners often first notice a firm swelling or lump near a limb joint, sometimes accompanied by lameness or stiffness that develops gradually. The mass may have been present for weeks or months before it becomes large enough to prompt concern. Because the signs can resemble other soft-tissue growths or joint problems, the nature of the lump is typically clarified through imaging and sampling. This page explores the patterns that may bring synovial cell sarcoma to attention, what is understood about how these tumours behave, the investigations used to characterise them, and the range of approaches that may be considered once a diagnosis is established.
Testicular Tumours
Testicular tumours are abnormal growths that develop in one or both testicles of intact male dogs. They arise when cells in the testicular tissue begin to multiply in an uncontrolled way, forming a mass that can vary in size and behaviour. Some testicular tumours grow slowly and remain contained within the testicle, while others can produce hormones that affect behaviour, coat quality, or other parts of the body. Owners often notice a change in the size, shape, or firmness of one testicle, or observe that the two testicles no longer feel symmetrical. In some cases, the first signs are not related to the testicles themselves. These can include hair loss, skin changes, behavioural shifts, or changes in the way other dogs respond to the affected animal. Occasionally, a testicular mass is found during a routine examination when no outward signs have been noticed. This page explores what signs may be observed, what processes lead to different types of testicular tumour, how they are investigated, and what approaches exist once a tumour is identified. The goal is to help orient your understanding of what may be happening and what the shape of the conversation with your veterinary team might look like.
Transitional Cell Carcinoma
Transitional cell carcinoma is the most common bladder cancer in dogs, arising from the cells lining the urinary tract, typically occurring in older dogs and causing urinary signs that can initially resemble infection or other bladder conditions.
Diagnostics & Monitoring
Anaemia of Chronic Disease
Anaemia of chronic disease, now often called anaemia of inflammatory disease, is a pattern in which the body's red blood cell count drops as part of its response to ongoing inflammation, infection, or illness elsewhere. The marrow has the capacity to make new cells, but iron becomes trapped inside storage cells and signalling changes mean fewer red cells are released into circulation. This type of anaemia usually builds over days to weeks rather than suddenly. In cats, a fall in red cells can show within about a week of inflammation starting. Owners may notice subtle changes: less enthusiasm for walks, sleeping more, or pale gums, but often the anaemia is detected on blood tests run for another reason, such as investigating weight loss, recurring infections, or a known chronic condition like kidney disease or immune-mediated illness. Because the anaemia is mild to moderate in many cases, signs can be easy to miss at first. This page explores the signals that may prompt investigation, the mechanisms that link inflammation to reduced red cell numbers, how anaemia of chronic disease is distinguished from other causes of low red cell counts, and the approaches taken when this pattern is identified. The focus is always on the underlying condition driving the process.
Anal Gland Disease
Anal gland disease describes a spectrum of problems affecting the paired scent glands that sit just inside the anus in dogs. These glands normally release a small amount of fluid when an animal passes faeces, but the ducts can become blocked, the glands can overfill, or infection can develop. What owners most often notice is scooting (dragging the bottom along the ground) or persistent licking and attention to the area under the tail. The signs can range from mild discomfort and a distinctive smell to visible swelling beside the anus, pain when sitting, or occasionally a ruptured abscess that breaks through the skin. Some animals experience isolated episodes; others develop a pattern that recurs over months or years. The underlying causes vary, and not all cases follow the same course. This page explores what anal gland disease can look like in practice, the mechanisms that contribute to blockage or infection, how the condition is investigated, and the range of approaches that may be considered, from manual expression and dietary adjustment to surgical removal, depending on severity and frequency.
Anal Gland Disease in Dogs
Anal gland disease refers to a collection of problems affecting the two small scent glands that sit on either side of a dog's anus. These glands normally release a small amount of fluid when the dog passes a firm stool, but when something disrupts that process (blockage, inflammation, infection or structural change), the gland can become uncomfortable, overfull, or damaged. Owners often notice scooting (dragging the bottom along the ground), licking or biting around the tail base, a sudden strong smell, or visible swelling to one side of the anus. Some dogs show discomfort when sitting or seem reluctant to lift their tail. The behaviour can appear suddenly or build gradually, and the severity ranges from mild irritation to pain that affects how the dog moves. This page explores what signs may suggest a problem with the anal glands, what processes underlie those signs, how the area is examined and what findings may emerge, and the range of approaches used depending on what is found. It does not cover every variant, but it provides a framework for understanding what may be happening and what the options tend to involve.
Angiostrongylus (Lungworm)
Angiostrongylus vasorum is a parasitic worm that lives in the blood vessels of the heart and lungs. Dogs become infected mainly by swallowing slugs or snails that carry the larval stage, and these can be very small and eaten by accident. Frogs can also carry the larvae. Foxes are also infected and act as a wildlife reservoir. Once inside the body, the larvae migrate to the pulmonary arteries, where they mature. Adult females lay eggs that lodge in the small blood vessels of the lungs and hatch into larvae, which break into the airways and are coughed up, swallowed and passed in faeces. Many dogs show no outward signs for weeks or months. When signs do appear, they can vary widely: some dogs develop a persistent cough or become tired more easily, others may bleed unusually after minor injuries or show unexplained bruising, and a smaller number experience more severe breathing difficulty or neurological changes such as seizures or loss of balance. Bleeding or neurological signs can appear suddenly, sometimes in a dog with no cough at all, and the infection can be fatal. The variety of presentations can make the picture unclear at first. This page explores what lungworm infection can look like in practice, how the parasite affects different body systems, the tests used to detect it, and the treatment approaches available. It also considers prevention strategies and what tends to happen after treatment begins.
Aortic Stenosis
Aortic stenosis is a narrowing of the heart's aortic valve or the region just above or below it, restricting the flow of blood as it leaves the left ventricle and enters the body's main circulation. The narrowing can range from mild to severe, and many affected dogs live without obvious signs for years, whilst others develop limitations in exercise tolerance, episodes of weakness, or collapse. Owners often arrive on this page after a heart murmur has been detected during a routine examination, or because a young dog has shown fatigue or breathlessness during exercise that seems out of proportion to the activity. In some cases the condition is discovered incidentally, in a dog that appears entirely well. This page explores the signals that can accompany aortic stenosis, the structural and functional changes that underlie them, the ways the condition is investigated and graded, and the range of approaches used to manage dogs across the spectrum of severity.
Arrhythmogenic Right Ventricular Cardiomyopathy (Boxer Cardiomyopathy)
Arrhythmogenic right ventricular cardiomyopathy is a heart condition seen predominantly in Boxers, in which the muscle of the right side of the heart is gradually replaced by fatty or fibrous tissue. This replacement tissue cannot contract normally, and it tends to generate abnormal electrical signals, leading to irregular heart rhythms. The condition can present in different ways: some dogs develop an irregular heartbeat that is noticed during a routine examination, while others may faint during exercise or excitement, and in some cases the first sign is sudden collapse. The severity and progression vary considerably between individuals. Some dogs live for years with careful monitoring and medication to control the rhythm disturbances, while others deteriorate more quickly or experience life-threatening arrhythmias. Because many affected dogs pass through a phase without outward signs, the condition may be detected on screening or incidentally in Boxers that appear otherwise healthy. This page explores the signs that may prompt investigation, the mechanisms underlying the rhythm disturbances and muscle changes, the diagnostic tests used to assess the heart's structure and electrical activity, and the range of approaches used to manage the condition over time.
Conjunctivitis
Conjunctivitis describes inflammation of the conjunctiva, the thin, moist tissue that lines the inner surface of the eyelids and covers the white of the eye. When this tissue becomes irritated or infected, it can swell, redden, and produce discharge. The change is often visible as redness around or within the eye, a watery or thicker discharge that may collect at the corner or along the lashes, and sometimes a narrowed appearance if the eye is uncomfortable. Owners often notice one or both eyes looking different: pinker than usual, weepy, or with a crust that builds up overnight. The pet may rub at the face, blink more frequently, or seem bothered by light. Sometimes the signs appear quickly after an obvious event, such as dust or pollen exposure; in other cases they develop gradually without a clear trigger. Conjunctivitis can occur alone or as part of a broader pattern involving other structures of the eye or body. This page explores what conjunctivitis can look like in daily life, the range of causes and mechanisms that can produce it, how it is distinguished from other conditions affecting the eye, and the forms of management that exist depending on what is driving the inflammation.
Constipation and Megacolon in Cats
Constipation describes difficulty passing faeces, or passing faeces less often than usual. In cats, this may appear as straining in the litter tray, producing small or hard stools, or none at all. Megacolon is a related condition in which the large bowel becomes stretched and loses its ability to move material forward effectively, often developing after repeated or prolonged episodes of constipation. Owners typically notice a cat spending longer than usual in the litter tray, sometimes vocalising or appearing uncomfortable, or they may find no faeces in the tray for a day or more. In some cases, a cat may strain in a way that looks the same as straining to pass urine, and a blocked urethra is the more dangerous of the two possibilities. The severity of constipation ranges widely, from a single mild episode that resolves on its own to a persistent pattern that requires investigation. This page explores what constipation and megacolon can look like in practice, the range of underlying factors that may contribute, how the problem is investigated, and the spectrum of approaches used to manage it. The aim is to help you understand what may be happening and what questions might be useful to consider.
Dystocia
Dystocia describes difficulty or inability to deliver young during labour. It can occur when contractions are weak or absent, when a puppy or kitten is positioned awkwardly or is too large to pass, or when the mother's pelvis or birth canal cannot accommodate normal delivery. Owners most often become concerned when strong straining produces no puppy or kitten within about 30 minutes, when weak or intermittent straining continues for more than an hour between deliveries or, in a bitch, a quiet pause runs past two hours, or when first-stage signs such as restlessness, nesting and panting continue beyond 24 hours without active labour beginning. The condition ranges from a single puppy lodged in the canal to complete failure of labour to begin. Some cases respond to medical treatment or assisted delivery; others require a caesarean section. Whether the cause is weak contractions or a physical blockage, and whether the unborn young are still alive, cannot be judged from outside and is established through examination and imaging. The outcome depends on how quickly the situation is identified, the specific mechanical or physiological cause, and the wellbeing of both mother and young during the process. This page explores the early signals that labour may not be progressing normally, the anatomical and hormonal factors that can contribute, the ways clinicians assess the situation, and the range of approaches, from medical support of contractions to caesarean section, that may be considered depending on the underlying cause and clinical picture.
Foreign Body Ingestion
Foreign body ingestion describes the situation in which a dog or cat swallows something that cannot be digested: a piece of toy, fabric, bone fragment, string, or any number of household objects. What happens next depends on the size, shape, and material of the object, and where it travels or lodges within the digestive tract. Owners often arrive at this page because they witnessed the ingestion, found evidence that something is missing, or have noticed vomiting, reduced appetite, or changes in behaviour over hours or days. In some cases the object passes through without incident; in others it becomes stuck, causes irritation, or creates a blockage that prevents normal movement of food and fluid. This page explores the signs that may appear, the mechanisms by which foreign material causes harm, the imaging and clinical approaches used to locate and assess the object, and the range of options, from monitoring to endoscopic retrieval to surgery, that may be considered depending on what has been swallowed and where it has travelled.
Gastric Dilatation-Volvulus (GDV) in Dogs
Gastric dilatation-volvulus describes a sequence in which a dog's stomach fills with gas and then rotates on itself, trapping that gas and cutting off blood flow to the stomach wall and sometimes to other organs. The rotation can happen partially or completely, and once it begins, the stomach continues to expand because the gas cannot escape. This is a mechanical problem with profound effects on circulation and tissue viability. Owners most often notice a dog whose abdomen appears swollen or tight, who may be restless, retching without bringing anything up, or standing in an anxious posture. The signs can appear quite suddenly, often in the hours after a meal or a period of activity, though the timing varies. Some dogs show only subtle discomfort at first, but mild early signs do not mean the stomach has not twisted, and the picture can change markedly over a few hours. This page explores what tends to be visible from the outside, what is happening inside the abdomen and the rest of the body when the stomach has twisted, how the condition is confirmed, and the approaches used to address it. It also considers which dogs may be more likely to experience this, and what is understood about the factors that may contribute.
Gastric Dilatation-Volvulus (GDV/Bloat)
Gastric dilatation-volvulus describes a sequence in which a dog's stomach fills with gas and then rotates on itself, trapping that gas and cutting off blood flow to the stomach wall and other organs. The rotation can happen rapidly, and the combination of pressure and compromised circulation affects the whole body. It occurs almost exclusively in dogs, particularly those with deep, narrow chests. Owners most often notice a swollen abdomen that feels tight or drum-like, along with unproductive retching: attempts to vomit that bring nothing up. The dog may seem restless, uncomfortable, or quieter than usual. Some dogs show drooling, pacing, or a hunched posture. The signs can appear suddenly, sometimes within hours of a meal or exercise, though the link is not always clear. This page explores what can be seen from the outside, what is happening inside the abdomen and circulation, how the condition is confirmed through imaging and examination, and the approaches used to address both the mechanical problem itself and the consequences that follow.
Gastroenteritis in Dogs
Gastroenteritis describes inflammation of the stomach and intestines. When this happens, the lining of the digestive tract becomes irritated or inflamed, and the normal processes of digestion and absorption can be disrupted. The result is often vomiting, diarrhoea, or both, sometimes alongside signs of discomfort or reduced appetite. Many owners arrive at this page after observing sudden changes in their dog's toileting or eating patterns, such as soft stools, repeated vomiting, or a reluctance to finish meals. These signs can appear after a dietary indiscretion, during a change in routine, or without an obvious trigger. The pattern can range from a single brief episode to something that persists or recurs. This page explores what gastroenteritis can look like in dogs, what may be happening beneath the surface, how the condition is investigated, and the range of approaches used to support recovery. It does not diagnose your dog, but it may help you understand what questions are being asked and why.
Intestinal Parasites
Intestinal parasites are organisms that live in the digestive tract of dogs and cats, drawing nutrients from the host and sometimes causing visible signs. The types most commonly encountered in the United Kingdom include roundworms and tapeworms in both dogs and cats, and hookworms and whipworms, which here are found mainly in dogs. Protozoa such as Giardia also occur. The specific parasites vary by species, age, and lifestyle. Many owners arrive on this page after observing changes in stools, such as segments that resemble grains of rice, visible worms, mucus, or diarrhoea, or because a routine faecal sample has returned a positive result. In other cases, there may be no outward signs at all, particularly in adult animals with low parasite burdens. Young animals, those with outdoor access, or pets in multi-animal households tend to encounter parasites more frequently. A heavy burden can make a puppy or kitten seriously ill, and some of these parasites, including the common roundworms, can also infect people. This page explores what different parasites look like when they cause signs, how they are transmitted, the diagnostic methods used to identify them, and the range of treatment and prevention approaches available. The goal is to help you understand what may be happening and how these infections are investigated and managed over time.
Megaoesophagus in Dogs
Megaoesophagus describes a condition in which the oesophagus (the muscular tube that carries food from the mouth to the stomach) loses its ability to move food effectively. Instead of contracting in coordinated waves, the oesophagus becomes enlarged and floppy, and swallowed material tends to sit in place or come back up. This can happen because the nerves or muscles controlling the oesophagus are not working as they should, or because something else in the body is interfering with that signalling. Owners often notice regurgitation: food or water coming back up soon after eating or hours later, sometimes undigested and without the forceful abdominal effort seen with vomiting. Some dogs may stretch their necks, make gulping movements, or seem hungry despite eating. Weight loss can develop because food does not reach the stomach, and coughing or difficulty breathing can develop if material enters the airways. The pattern and timing of these signs can vary depending on what is driving the problem and how severe it has become. This page explores what megaoesophagus looks like in daily life, what may be causing it, how it is investigated through imaging and other tests, and what approaches exist to support affected dogs. The aim is to help you understand the condition, recognise its variations, and orient yourself for conversations about management.
Nasopharyngeal Polyps
A nasopharyngeal polyp is a benign growth that arises from the lining of the middle ear or Eustachian tube and grows into the back of the nasal passages (the nasopharynx) or the ear canal, most often in young cats and rarely in dogs. These growths are not cancerous, but they can occupy space in narrow airways and interfere with normal breathing, swallowing, or hearing depending on where they sit and how large they become. Owners often notice noisy breathing, snoring sounds that seem new, discharge from one or both nostrils, difficulty swallowing, or a head tilt if the inner ear becomes involved. The signs can develop gradually and may be mistaken for a persistent upper respiratory infection, particularly when discharge is present. In some cases, a fleshy mass may be visible at the back of the throat. This page explores what these signs can indicate, the structures involved and how polyps form, the diagnostic steps used to locate and characterise the growth, and the approaches available for removal. The goal is to help you understand what may be happening and what the investigative and management pathway typically looks like.
Pericardial Effusion
Pericardial effusion involves accumulation of fluid within the sac surrounding the heart, which can compress the heart and impair its function, presenting with signs of cardiovascular compromise. When fluid builds quickly, this compression, called cardiac tamponade, can cause collapse and can be fatal within hours; draining the fluid relieves it.
Systemic Hypertension in Cats
Systemic hypertension describes sustained high pressure within the blood vessels that circulate throughout the body. In cats, this is most often a consequence of other conditions, particularly chronic kidney disease and hyperthyroidism, rather than a standalone problem. The elevation in pressure can be present for months without producing visible changes, or it can lead to sudden signs when delicate structures, especially in the eyes or brain, are affected. Many owners first become aware of the possibility when a cat's eyes change abruptly, with pupils that stay wide, blood visible inside the eye, or sudden blindness, or when routine blood tests prompt a blood pressure check. Some cats show no outward signs at all, and raised pressure is identified only during monitoring for another condition. This page explores what elevated blood pressure looks like in practice, how it is measured and interpreted, the organs most often affected, and the ways it can be managed alongside the conditions that tend to drive it.
Urethral Obstruction
Urethral obstruction occurs when the tube that carries urine from the bladder to the outside (the urethra) becomes blocked, preventing a cat or dog from emptying their bladder normally. The blockage can be partial or complete, and may develop over hours or days. Male cats are particularly prone, though it can occur in any cat or dog. Owners often notice repeated trips to the litter tray or garden with little or no urine produced, straining that may resemble constipation, or vocalisation during attempts. Some animals may lick at the area persistently or seem restless and uncomfortable. The early signs look much like those of cystitis or constipation, and whether the bladder is emptying cannot be judged at home. A complete blockage is life-threatening, with death reported in less than 24 to 48 hours. This page explores the patterns that may prompt concern, what can cause or contribute to a blockage, how the condition is confirmed and monitored, and the range of approaches used to relieve the obstruction and support recovery. The focus is on helping owners recognise what they may be observing and understand the shape of the problem.
Urinary Incontinence
Urinary incontinence describes the involuntary loss of urine: leakage that happens without the animal making a conscious decision to urinate. It can appear as damp patches on bedding, wet fur around the back legs or tail base, or drips left behind when the animal stands up. Some owners notice it only at night or when the pet is deeply asleep; others see it throughout the day. The underlying causes vary widely. In some cases the bladder neck or urethral sphincter does not maintain its usual tone, often linked to hormonal changes after neutering in female dogs. In others the bladder itself may be overactive, scarred, or positioned unusually. Neurological conditions, developmental anatomy, chronic inflammation, and age-related changes all appear in the clinical picture. This page explores what incontinence can signal, the mechanisms that may be at work, the diagnostic steps that help distinguish one cause from another, and the range of medical and surgical approaches used to manage it. The goal is to help you understand the shape of the problem and the questions that structure the investigation.
Unassigned
Cataracts in Dogs
A cataract is an opacity that forms in the lens of the eye. The lens normally sits behind the pupil and is transparent, allowing light to pass through to the retina at the back of the eye. When the lens becomes cloudy, vision is affected to varying degrees, from small areas of haze that may go unnoticed to complete whiteness that can lead to blindness. Owners often first notice a cloudiness or white appearance in one or both eyes, or they may observe that their dog is bumping into objects, hesitating on stairs, or becoming more cautious in dim light or unfamiliar places. Cataracts can appear at any age, from puppies to older dogs, and may develop rapidly or progress slowly over months or years. Not all cloudiness in the eye is a cataract: a normal age-related change called nuclear sclerosis can also cause a greyish haze but does not typically interfere with vision. This page explores what cataracts look like and how they may be identified, what causes them to form, how they are investigated, and the range of approaches available depending on the extent of cloudiness and how the dog is affected.
Elbow Dysplasia in Dogs
Elbow dysplasia is a term that describes a group of developmental conditions affecting the elbow joint in young, growing dogs. The joint may not form in the expected way, leading to areas of cartilage or bone that do not sit flush, fragment, or wear unevenly. Over time, this can create inflammation, discomfort, and changes to the joint surface. Owners often notice a young dog beginning to favour one or both front legs, particularly after rest or exercise, or moving with a slightly stiff or shortened stride. The signs can be subtle at first: a reluctance to play, a shift in how the dog rises from lying down, or a persistent limp that comes and goes. In some cases, the dog may hold the affected leg out slightly or show discomfort when the elbow is moved through its full range. This page explores what signals may prompt concern, what may be happening inside the joint, how the condition is investigated through examination and imaging, and the range of approaches that exist, from managing inflammation and load, to surgical options in selected cases.
Tracheal Collapse in Dogs
Tracheal collapse describes a progressive weakening of the cartilage rings that normally hold the windpipe open. As the structural support fails, the trachea flattens during breathing, particularly when air is moving quickly or when pressure changes inside the airway. This creates turbulent airflow and the characteristic sounds and effort that often prompt concern. Many owners first notice a dry, honking cough that may worsen with excitement, exercise, or pressure on the neck from a collar. Some dogs develop a more laboured breathing pattern, particularly in warm weather or during exertion. The condition occurs most often in small-breed dogs, and signs can appear at any age, though middle-aged and older animals are more commonly affected. This page explores what can be observed when the trachea is collapsing, the mechanisms that drive those signs, how the condition is identified and characterised, and the range of approaches used to manage it over time.
Vestibular Disease in Dogs
Vestibular disease describes a disruption to the system that helps dogs maintain balance, coordinate movement, and know where they are in space. This system relies on structures in the inner ear and parts of the brain working together to process signals about position and motion. When something interferes with these signals, the result can be a sudden loss of coordination that often looks alarming: a head tilt, eyes flicking side to side, difficulty standing, or circling in one direction. Owners often describe their dog as appearing drunk, dizzy, or as though the world has tilted. The signs can appear very quickly, sometimes within hours, and the intensity varies widely. Some dogs remain alert and aware but unsteady; others may be reluctant to move or may fall repeatedly to one side. Whether the problem lies in the inner ear or in the brain cannot be judged from how a dog looks at home; the features that separate the two, such as the character of the eye movements, awareness, and how the feet are placed, are assessed in a neurological examination. This page explores what vestibular disease can look like in practice, what may be happening beneath the surface, how the location and cause are investigated, and what approaches exist depending on the underlying picture. The course and outlook depend heavily on the cause, which ranges from a self-limiting idiopathic disturbance of the inner ear, through middle and inner ear infection and drug toxicity, to inflammation, tumours and infarcts in the brain, where outcome can depend on how early the cause is identified.