SYMPTOM
Head pressing
Owners describe the animal standing with its head pushed against a wall, furniture, or into a corner for sustained periods, often appearing to seek out solid contact rather than resting normally, sometimes alongside a glazed expression, disorientation, or reduced responsiveness to its name. This differs from ordinary head rubbing or bunting in cats, and from a dog leaning its head into a person for attention. Those are brief, directed at people or familiar objects, and the animal stays alert and engaged. True head pressing has no recognised normal or harmless explanation; it reflects a change in how the forebrain is working.
Hepatic Encephalopathy
When the liver cannot adequately clear ammonia and other nitrogenous by-products from the bloodstream, these substances accumulate and disrupt normal brain function. Head pressing is one of the recognised changes, alongside disorientation, pacing, circling or apparent blindness. Signs often wax and wane and can worsen after a meal, and an episode can deepen over hours into stupor, seizures or coma. In cats, heavy drooling is a common accompanying sign. Blood ammonia and liver function can only be assessed with blood tests.
Congenital Vascular Shunting
A portosystemic shunt allows blood from the intestines to bypass the liver's filtering function, so toxins that would normally be cleared reach the brain directly. This is more often recognised in young animals, sometimes alongside stunted growth.
Structural Brain Disease
A space-occupying lesion such as a meningioma exerts pressure on surrounding forebrain tissue. Head pressing can appear alongside other forebrain signs such as circling, behavioural change, or seizures, more typically in older animals.
Inflammatory Brain Disease
Non-infectious inflammatory conditions affecting the brain, such as necrotising or granulomatous meningoencephalitis, disrupt normal forebrain function directly. These are recognised more frequently in certain small-breed dogs.
Cerebrospinal Fluid Accumulation
Hydrocephalus involves a build-up of fluid within the skull that raises intracranial pressure and distorts brain tissue. This pattern is more often recognised in young, particularly toy-breed, dogs.
Hypertensive Encephalopathy
Sustained elevation in blood pressure, frequently secondary to underlying kidney or endocrine disease in cats, can affect brain perfusion. Neurological signs include disorientation, dullness, wobbliness and seizures, and head pressing has been described. Sudden blindness from retinal detachment, often with widely dilated pupils, is a common companion sign. Blood pressure can only be measured with equipment in a clinic.
Traumatic Brain Injury
A blow to the head, such as from a road traffic accident or a fall, can raise pressure within the skull and disrupt forebrain function in the hours to days that follow. Head pressing appearing after a known knock or accident fits this pattern rather than a spontaneous metabolic or structural process. Swelling after the initial injury can build over the first hours to days, so an animal that seems only dazed soon after a knock can deteriorate later. Increasing dullness, pupils of unequal size and abnormal breathing mark a worsening picture.
Toxin Exposure
Lead is the toxin most classically linked with head pressing, alongside behavioural change, blindness, tremors or seizures, and often vomiting or abdominal discomfort. Sources include old lead-based paint disturbed during renovation of older houses, and lead objects such as fishing weights or shot. A pet affected by lead can also point to a source that matters for people in the same household, particularly young children. Other poisons that act on the brain, such as antifreeze (ethylene glycol) and the alphachloralose rodenticides used in the UK, more often cause wobbliness, tremors, dullness, low body temperature or seizures. Antifreeze produces these signs within roughly 30 minutes to 12 hours of ingestion, and its antidote tends to work only within about the first three hours in cats and the first 8 to 12 hours in dogs, before kidney damage is established.
Infectious Brain Disease
Infections of the brain can disrupt forebrain function and produce head pressing, behavioural change or seizures. In young cats, the neurological form of feline infectious peritonitis (FIP) is the most frequent cause of neurological disease. Toxoplasmosis is also recognised in cats, and cryptococcosis, a fungal infection, is a rare, sporadic cause in the UK. In dogs, canine distemper is uncommon in the UK because of vaccination but still occurs, particularly in unvaccinated or imported dogs, and a chronic form of distemper encephalitis is described with compulsive pacing and head pressing. Toxoplasma is zoonotic: people are most often infected from undercooked meat, and less often from cat faeces, which only become infectious a day or more after they are passed. Rabies, a notifiable disease, does not occur in UK dogs and cats and is relevant only where there is an import or travel history in the preceding months.
Why timing matters
Early observation
Head pressing reflects a change in forebrain function, so even a single brief episode is clinically meaningful rather than incidental. An episode that settles does not show that the cause has settled: hepatic encephalopathy can wax and wane before more severe episodes, swelling after a head injury can build over hours to days, and some poisons have treatment windows measured in hours. Whether the cause is metabolic, toxic, infectious, inflammatory, vascular or structural cannot be judged from the behaviour itself; it rests on examination, blood tests, blood pressure measurement and often brain imaging.
Later presentation
Head pressing that persists, recurs, or is accompanied by a gradual decline in alertness or coordination suggests an ongoing process, whether structural, inflammatory, or metabolic, that has had time to progress. Longer-standing presentations are more often associated with a lesion that has continued to grow or an underlying disease process that has continued to advance.
The pace of onset is informative: a sudden onset in a previously well animal fits a metabolic, toxic, traumatic or vascular event, or an acute inflammatory or infectious brain disease, whereas a slowly progressive pattern over weeks to months is more typical of a tumour or other gradually enlarging lesion. A slow course does not rule out a sudden change: a brain tumour can decompensate abruptly once swelling or bleeding pushes pressure within the skull beyond what the brain can accommodate. Whether the episodes seen so far have been isolated, clustered or close to continuous helps place the presentation along that spectrum.
Conditions commonly associated
Hepatic Encephalopathy
Accumulation of ammonia and other toxins normally cleared by the liver disrupts brain function and is a recognised cause of head pressing alongside disorientation.
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Portosystemic Shunt
Blood bypassing the liver's detoxification function allows circulating toxins to affect the brain directly, producing head pressing often in young animals.
Meningioma
This is the most common primary brain tumour in dogs and cats, and its mass effect on forebrain tissue can produce head pressing alongside other behavioural or seizure activity.
Necrotising Meningoencephalitis (NME)
Non-infectious inflammation of the brain, recognised particularly in small-breed dogs, directly disrupts forebrain function and can present with head pressing.
Granulomatous Meningoencephalomyelitis (GME)
Inflammatory infiltration of the central nervous system can affect forebrain regions and produce head pressing alongside other neurological signs.
Hydrocephalus
Accumulation of cerebrospinal fluid raises intracranial pressure and distorts brain tissue, a recognised cause of head pressing particularly in young toy-breed dogs.
Systemic Hypertension in Cats
Sustained high blood pressure can affect cerebral perfusion and has been associated with altered behaviour, including head pressing, particularly in cats with underlying kidney or thyroid disease.
Pituitary Macroadenoma
A large pituitary tumour, most often recognised in dogs with pituitary-dependent Cushing's disease, can compress the overlying brain and cause dullness, disorientation, pacing and head pressing.
Glioma in Dogs
Gliomas are primary brain tumours over-represented in brachycephalic breeds, and a mass in the forebrain can cause seizures, behavioural change and head pressing.
Feline Infectious Peritonitis (FIP)
The neurological form of FIP is the most frequent cause of neurological disease in young cats and can produce behavioural change, seizures and forebrain signs such as head pressing.
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Toxoplasmosis
Toxoplasma infection of the brain, often a reactivation in an immunosuppressed cat, can cause behavioural change and other forebrain signs. The parasite is zoonotic, most often reaching people through undercooked meat and less often through cat faeces.
Canine Distemper
Distemper virus can infect the brain, and chronic distemper encephalitis is described with compulsive pacing and head pressing. The disease is uncommon in the UK but still occurs, particularly in unvaccinated or imported dogs.
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When to explore further
Head pressing that appears alongside disorientation, circling consistently in one direction, or a noticeable change in personality adds to the evidence of forebrain involvement; the exact site and cause cannot be pinned down without a neurological examination and, often, blood tests and brain imaging.
A young dog or cat with a history of poor growth, or one that shows the behaviour particularly after eating a protein-rich meal, fits a pattern sometimes seen with a congenital vascular shunt.
An older animal in which head pressing develops gradually alongside subtle vision changes or behavioural drift benefits from evaluation rather than observation alone, given the association with structural brain disease at this life stage.
Head pressing that follows known liver disease, or occurs alongside jaundice, reduced appetite, or excessive drinking, may reflect a metabolic rather than primary neurological process.
Sudden onset in an older cat with a known history of kidney disease or an overactive thyroid may reflect a blood pressure contribution rather than primary brain pathology.
Head pressing together with deepening dullness, unresponsiveness, seizures, pupils of unequal size, sudden blindness or irregular breathing describes a brain under increasing pressure or metabolic strain. These changes can progress over minutes to hours, and their causes cannot be separated at home.
Head pressing within hours or days of a fall, road traffic accident or other knock to the head, or after possible access to antifreeze, rodenticide, old paint or an unknown substance, belongs to a group of causes where the outcome depends heavily on how early treatment begins.
A short video of an episode, including how the animal responds to its name and whether it appears aware of its surroundings, adds objective detail beyond a verbal description. Details that change the likely causes include any possible knock to the head, access to antifreeze, rodenticides, old paint or other unusual substances, the timing of episodes relative to meals, drooling, any circling direction, changes in vision, appetite or thirst, poor growth in a young animal, and known liver, kidney or thyroid disease. The time head pressing was first seen is also worth recording, because several of its causes change over hours rather than days.
Last reviewed: 9 October 2026 · Dr Alastair Greenway MRCVS