CONDITION
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.
Why this matters now
Discospondylitis tends to affect middle-aged to older dogs, often around four to seven years of age or older, though cases can occur outside this range. Larger breeds appear over-represented in clinical series, possibly reflecting greater mechanical stress on the spine or other factors not yet fully understood. Male dogs may be affected somewhat more frequently than females. The condition often follows an infection elsewhere in the body—urinary tract, skin, mouth, or respiratory system—though in many cases no obvious source is identified. Import from, or travel to, countries where Brucella canis is endemic, particularly in Eastern Europe, is a recognised risk factor. Brucella canis is not established in the native UK dog population, but it is being diagnosed increasingly in imported dogs, and both dog-to-dog and dog-to-human transmission have been reported in the UK.
The course can vary considerably between individuals. Some animals develop signs gradually over several weeks, with subtle stiffness or reduced activity noticed before pain becomes more apparent. In other cases the onset appears more sudden, with marked pain or reluctance to move developing over a few days. Without intervention the infection can persist, leading to progressive destruction of disc and bone, increasing pain, and in some cases neurological deterioration if the spinal cord becomes compressed. Weakness, wobbling, scuffing or dragging of the limbs that appears or worsens can progress over days, and the extent of spinal cord involvement cannot be judged at home. In a large multi-institutional study, dogs that had received corticosteroids before diagnosis were more likely to show progressive neurological decline, which is relevant because back pain is sometimes treated with steroids before an infection has been identified. Early recognition and management can alter the trajectory, though the timeline for improvement is often measured in weeks to months rather than days.
Signals & patterns
Early signals
Reluctance to jump or climb
The dog may hesitate before jumping onto furniture or climbing stairs, or may avoid these activities altogether. This often reflects pain generated by spinal movement or the mechanical load placed on the affected area.
Stiffness after rest
Movement may appear restricted or guarded when the animal first stands after lying down, sometimes easing slightly with gentle activity. The stiffness tends to be most noticeable in the portion of the spine where the infection is seated.
Hunched or arched posture
The back may appear rounded or tense, particularly when standing or walking. This postural change often represents an attempt to reduce movement and mechanical stress in the painful segment of the spine.
Reduced appetite or low energy
Some dogs become quieter or less interested in food, particularly if there is systemic inflammation or low-grade fever accompanying the spinal infection. These signs can precede the more obvious pain-related behaviours.
Sensitivity when touched along the back
The dog may flinch, tense, or pull away when the spine is touched or pressed, especially over the affected disc. Some animals may vocalise or turn toward the person touching them.
Fever or systemic signs of illness
Some dogs have a raised body temperature, lethargy or other signs of inflammation beyond the spine, and these can appear at any stage rather than only late in the disease. Fever is absent in most confirmed cases, so a normal temperature does not make discospondylitis less likely.
Later signals
Weakness or incoordination in the limbs
If swelling, structural collapse, or new bone formation begins to compress the spinal cord, the signals it carries to the limbs may be disrupted. This can appear as wobbling, scuffing or dragging of the feet, or difficulty rising. Once weakness appears it can worsen over days, and the degree of spinal cord compression cannot be judged from the outside.
Marked reluctance to move at all
Pain may become severe enough that the animal avoids standing or walking, remaining in one position for extended periods. This often reflects advanced infection, significant structural change, or both.
Click to read about the biological mechanisms
How this is usually investigated
Investigation typically begins with a careful history and physical examination, looking for spinal pain, fever, or signs pointing to infection elsewhere in the body. When discospondylitis is suspected, imaging of the spine is usually the next step, followed by blood tests to assess inflammation and infection markers. Attempts are often made to identify the specific organism responsible, which can guide the choice of antimicrobial therapy and, where Brucella canis is involved, carries public health and legal implications for the household.
Physical examination
Radiography
Magnetic resonance imaging or computed tomography
Blood tests
Blood culture or tissue sampling
Brucella canis testing
Options & trade-offs
Management typically combines antimicrobial therapy to address the infection, analgesia to manage pain, and measures to support spinal stability during healing. The combination and duration are individualised, reflecting the organism involved, the severity of signs, the presence of neurological deficits, and the owner's practical constraints. Some animals respond well to medical management alone, while others benefit from surgical intervention, particularly when the spinal cord is compressed or instability is marked.
Antimicrobial therapy
Antibiotics are the mainstay of treatment; courses of at least six to eight weeks are typical, but many cases require considerably longer therapy, with one large multi-institutional study finding a median treatment duration of around sixteen weeks, guided by clinical and radiographic response. The choice may be guided by culture and sensitivity results, or empirical selections are made based on the organisms most commonly implicated, such as Staphylococcus species. Oral or injectable formulations can be used, and the response is monitored through clinical improvement and repeat imaging.
Trade-offs: Long courses of antibiotics carry risks of gastrointestinal upset, development of resistant organisms, and financial cost. Some infections are slow to respond, and imaging changes may lag behind clinical improvement, making it difficult to judge when therapy can safely be stopped. Culture-negative cases require an element of empiricism in drug selection.
Pain management and activity modification
Analgesia—often involving non-steroidal anti-inflammatory drugs, opioids, or other pain-relieving medications—is used to keep the animal comfortable during the healing process. Activity is typically restricted to short, controlled walks on a lead, avoiding jumping, running, or rough play that could destabilise the spine or exacerbate pain. The degree of restriction and duration are adjusted as the animal improves.
Trade-offs: Strict rest can be difficult to enforce in energetic dogs, and prolonged confinement may lead to frustration or muscle loss. Analgesic medications can have side effects—gastrointestinal irritation, sedation, or effects on kidney function—that require monitoring, particularly during extended use.
Surgical debridement and stabilisation
Surgery may be considered when there is significant spinal cord compression, marked instability, or when medical management fails to control infection or pain. The procedure typically involves removing infected tissue from the disc space and sometimes fusing or stabilising the affected vertebrae with implants. Samples can be taken for culture at the same time.
Trade-offs: Spinal surgery carries risks including haemorrhage, further neurological injury, implant failure, and infection, and requires specialist expertise and postoperative rehabilitation. Recovery can be prolonged, and some animals experience persistent pain or neurological deficits. Surgery is a major undertaking both medically and financially.
Supportive care and monitoring
Regular reassessment—through clinical examination, blood tests, and repeat imaging—helps track response to treatment and guide adjustments in therapy. Nutritional support, physiotherapy, and nursing care may be needed, particularly in animals with reduced mobility or appetite. Owners are involved in monitoring pain levels, mobility, and signs of deterioration at home.
Trade-offs: Frequent veterinary visits and imaging studies add to the overall cost and time commitment. Progress can be slow, with visible improvement sometimes taking weeks, which can be discouraging. Not all animals regain full function, and some degree of residual stiffness or discomfort may persist even after infection is controlled.
Common misconceptions
"If the X-rays are normal, my dog cannot have discospondylitis."
Radiographic changes often lag behind the onset of infection by two to four weeks or more, meaning that early in the disease the spine may appear normal on X-ray. Advanced imaging such as MRI can detect changes sooner, and a negative radiograph does not exclude the diagnosis if clinical suspicion remains high.
"Once the antibiotics are finished, the infection is cured and the problem is over."
While many animals respond well to prolonged antimicrobial therapy, some experience relapse, persistent pain, or progressive structural changes even after treatment is completed. Healing of bone and disc takes time, and imaging abnormalities can persist long after clinical signs have improved. Ongoing monitoring is often part of the picture.
"Discospondylitis only affects the back, so lameness in a leg means something else is going on."
Spinal infections can cause referred pain or nerve root compression that manifests as lameness, dragging of a limb, or altered gait, particularly if the affected disc is in the lower back or neck. The signs are not always confined to obvious spinal pain or stiffness, and a thorough examination is needed to locate the source.
Related conditions
Osteomyelitis
Osteomyelitis shares the underlying mechanism of bacterial infection within bone tissue, though in discospondylitis the infection involves both the vertebrae and the intervertebral disc. Both conditions can arise through haematogenous spread from distant infection sites and may present with similar patterns of pain, fever, and systemic illness.
Septic Arthritis
Septic arthritis represents infection within a joint space, and the same bacteria that cause discospondylitis can occasionally seed joints through the bloodstream. Both conditions share investigative approaches—imaging, sampling of affected fluid or tissue, and microbial culture—and may occur together in animals with widespread bacteraemia.
Intervertebral Disc Disease (IVDD)
Intervertebral disc disease can present with similar signs of back pain, stiffness, and reluctance to move, though it arises from mechanical disc degeneration or extrusion rather than infection. Imaging is often needed to distinguish between the two, as both can cause spinal discomfort and, in some cases, nerve compression.
Pyelonephritis
Pyelonephritis is a bacterial infection of the kidneys that can serve as a source for haematogenous spread, allowing bacteria to reach the spine and establish discospondylitis. Dogs with urinary tract infections that ascend to the kidneys may be at higher risk for subsequent bloodstream seeding of the vertebrae.
Steroid-Responsive Meningitis-Arteritis (SRMA)
Steroid-responsive meningitis-arteritis involves immune-mediated inflammation of the membranes around the brain and spinal cord, and may initially be considered as a differential diagnosis in dogs presenting with spinal pain and fever. The two conditions differ in underlying cause—immune dysregulation versus infection—but imaging and cerebrospinal fluid analysis can help distinguish them.
Brucellosis in Dogs
Brucella canis is a recognised cause of discospondylitis, seen mainly in dogs imported from or with a travel history to endemic regions such as Eastern Europe. It is zoonotic and reportable to APHA in England, Scotland and Wales, so identifying it matters for the household and other dogs as well as the patient.
Understanding how pain and mobility are affected across a range of spinal and musculoskeletal conditions can provide useful context for the patterns seen here. If your animal is recovering, the timeline and expectations for rehabilitation may be worth exploring in a conversation that takes into account their individual progress and the findings on imaging. Other infections and inflammatory conditions that affect the spine or surrounding structures share some features with discospondylitis, and familiarity with those patterns can help make sense of what is being observed over time.
Last reviewed: 13 September 2026 · Dr Alastair Greenway MRCVS