Spondylosis in Dogs and Cats: Spinal Bone Spurs Guide

Spondylosis is one of those diagnoses that sounds far more alarming than it usually is. An owner brings an older pet in for something unrelated, a radiograph is taken, and the report mentions bony spurs bridging the vertebrae. The word bridging conjures images of a fused, immovable spine, and worry sets in before anyone has explained what the finding actually means.

In reality, spondylosis deformans is extremely common in older dogs and is also seen in cats, and in a great many patients it causes no clinical signs at all. Understanding when it matters and when it does not is the most useful thing an owner can learn about it.

This guide covers what spondylosis is, why it forms, when it becomes clinically relevant, how veterinarians tell it apart from other spinal conditions, and what home management looks like. If your pet is painful, weak, wobbly, or suddenly unable to walk, contact your veterinarian or an emergency clinic without delay.

Important: This article shares general educational information for pet owners and is not a substitute for an in-person veterinary examination, diagnosis, or treatment. For any medical concern or emergency, contact your veterinarian promptly.

What Spondylosis Deformans Actually Is

The spine is a stack of vertebrae separated by intervertebral discs, each acting as a cushion and a flexible joint. Discs age. Over the years they lose water content and elasticity, and the segment they support becomes less stable than it once was. The body responds the way bone responds to abnormal stress, by laying down more bone.

Spondylosis deformans is the name for the bony spurs, sometimes called osteophytes, that form along the vertebrae in response. They usually develop on the underside and sides of the vertebral bodies, growing outward from the edges near the disc space. When spurs from two neighboring vertebrae meet, they can form a bridge that visually links the two bones on a radiograph.

Where the spurs typically form

The most common locations are the lower back and the area near the tail base, and the mid to lower chest region is also frequently involved. In cats the same process occurs, often in the lower back. This bone is stabilizing a degenerating segment. It is a response to change over time, not an infection or a tumor.

Why It Is So Often an Incidental Finding

This is the most reassuring point in the whole subject, and also the most misunderstood. Spondylosis is very often found on radiographs taken for a completely different reason, such as a film before a dental procedure, an abdominal study, or a senior screening. The pet has no back pain, no weakness, and no change in behavior, yet the report mentions bridging spurs.

The reason is anatomical. The spurs form on the outside of the vertebral bodies, on the underside and flanks, whereas the spinal cord runs through a canal above them. Bone growing in that outer location typically grows away from the nerve tissue rather than toward it, so as long as the spurs stay where they usually form, there is nothing pressing on the cord.

A radiographic report describing extensive spondylosis in a comfortable, mobile pet is generally not a crisis, and it does not explain signs on its own. If a pet does have back pain or weakness, the finding must be matched to the physical examination before anyone concludes the spurs are responsible.

When Spondylosis Actually Matters

Sometimes it does matter, and dismissing every case as harmless would be as wrong as treating every case as a catastrophe. There are situations in which spondylosis contributes to discomfort or limits what a pet can do.

• Nerve root compression: if bone forms close to the opening where a nerve root exits the spine, it can irritate that nerve, causing pain, an odd gait, or hind limb lameness.
• Reduced spinal flexibility: extensive bridging across several segments can stiffen the back, so the pet cannot arch or turn as easily as before.
• Coexisting conditions: spondylosis often accompanies arthritis of the small spinal joints, hip arthritis, or disc disease, and the combination affects comfort more than any single finding.
• Fractured or irritated spurs: a large spur that is bumped or stressed can become a source of pain in its own right.
• Compensatory strain: a stiff back changes how a pet moves, loading other joints differently over time.

The rule your veterinarian will apply is simple: treat the patient, not the picture. A pet who is genuinely uncomfortable needs a plan regardless of how mild the radiographs look, and a comfortable pet needs monitoring rather than intervention no matter how dramatic the spurs appear.

Telling Spondylosis Apart From Other Spinal Conditions

Because spondylosis is so common in older pets, it easily becomes a convenient explanation for signs actually caused by something else, something more urgent or more treatable. An accurate diagnosis changes what happens next and how quickly.

Intervertebral disc disease

Disc disease involves disc material bulging or extruding into the spinal canal, where it presses on the cord. Signs can be sudden and severe, including acute pain, hind limb weakness, wobbliness, dragging paws, or an inability to walk. Sudden weakness or paralysis is an emergency needing immediate veterinary attention.

Lumbosacral disease

This affects the junction between the lower back and the pelvis, where several nerves exit. It can cause pain when the tail base is pressed, difficulty rising, reluctance to jump, hind limb lameness, and sometimes changes in tail carriage or continence. It may coexist with spondylosis in the same region.

Degenerative myelopathy

This is a progressive disease of the spinal cord seen in certain dog breeds. Its hallmark is slowly worsening hind limb weakness and incoordination that is characteristically not painful. A dog with weakness but no pain response needs careful neurologic evaluation rather than assumptions.

Which Dogs and Cats Are at Higher Risk

Spondylosis is fundamentally a wear and change condition, so the biggest factor is time. Many older dogs have some degree of it whether or not it affects them. Some groups are recognized as more likely to develop it, or to develop it earlier.

• Older pets: the strongest association, in both dogs and cats.
• Large and giant breeds: heavier bodies place more load through the spine over a lifetime.
• Predisposed breeds: boxers in particular are widely recognized as prone to extensive spondylosis, sometimes younger than expected.
• Previously injured spines: a segment damaged, strained, or involved in earlier disc disease is more likely to change.
• Overweight pets: excess body weight increases the load on every spinal segment.
• Working and highly athletic dogs: repeated high impact loading over years can contribute.

Cats deserve their own mention because they are so good at hiding discomfort. Feline spinal changes are underdiagnosed because cats do not limp obviously; instead they quietly stop doing things. Owners read those changes as an aging personality rather than a physical problem, so any behavioral change in an older cat is worth raising with your veterinarian.

Signs Owners May Notice in Dogs and Cats

When spondylosis is clinically relevant, the signs are about stiffness and reluctance rather than dramatic pain. They creep in slowly, which is why they get attributed to normal aging. Video taken at home of your pet rising, walking, and turning is useful, because animals move differently in a clinic.

In dogs

• Stiffness after rest: slow, careful rising after a nap that eases once the dog gets moving.
• Reluctance to jump or climb: hesitating at the car, the couch, or the stairs.
• A hunched or roached topline: the back held in an arched position rather than level.
• Sensitivity along the back: flinching, tensing, or turning when stroked over the lower back or tail base.
• Difficulty turning: a wide, awkward turn instead of an easy curl, or trouble reaching the flank to scratch.
• Changed tail carriage: a tail held lower or less expressively than usual.

In cats

• Reduced grooming of the lower back: a scurfy, unkempt coat over the rump because reaching back is uncomfortable.
• Hesitating before jumping: pausing at the counter, choosing a lower perch, or breaking one big jump into two.
• Litter box changes: trouble stepping over a high sided box, or avoiding it altogether.
• Reduced activity: sleeping more, playing less, and choosing accessible resting places.

How Veterinarians Diagnose It

Diagnosis has two halves that must be brought together: the pictures and the patient. Radiographs of the spine show spurs and bridges clearly and are the usual first step, although sedation is often used so the pet can be positioned properly without being manipulated while awake.

The other half is the examination. A thorough orthopedic and neurologic assessment checks gait, posture, reflexes, proprioception, muscle mass, and where pressure along the spine produces a pain response. This determines whether the spurs seen on the film have anything to do with the signs the owner reported, or whether the real problem lies elsewhere.

When advanced imaging is used

• CT: excellent for detailed bone anatomy and for mapping spurs near nerve exits.
• MRI: the best way to look at soft tissue, discs, nerve roots, and the spinal cord itself.
• Blood and urine testing: to assess general health, rule out other causes of weakness, and plan safe pain management.

Ask your veterinarian how the imaging findings match the examination. If the two do not line up, further investigation is warranted rather than settling on the easiest available label.

The Management Landscape

For pets with no clinical signs, the plan is sensible monitoring: keep the pet lean, keep it moving, and mention any change in mobility at future visits. For pets who are genuinely affected, management is multimodal, meaning several modest interventions combined achieve more than any one alone.

Surgery is uncommon for spondylosis itself, and is considered only in selected cases where a structure is clearly compressing a nerve. That decision belongs with your veterinarian and usually a specialist.

Home Adaptations That Make Daily Life Easier

Environmental changes are often the most immediately effective thing an owner can do, and they cost little. The goal is to remove the movements a stiff spine finds difficult, particularly twisting, stretching upward, and landing from a height.

• Ramps and steps: a ramp into the car and pet steps to a favorite couch remove repeated jumping and landing.
• Orthopedic bedding: a supportive, thick mattress in a draft free spot, low enough to step onto rather than climb into.
• Non-slip runners: rugs or grip mats along the routes a pet uses most, so there is no scrambling on tile or hardwood.
• Raised bowls where appropriate: some pets are more comfortable eating without stooping, though this is not right for every patient, so ask first.
• Low entry litter boxes: for cats, a box with one low side, placed on every floor, avoids painful climbing.
• Warm resting places: a quiet spot away from drafts, since cold surfaces make stiff bodies stiffer.
• Nail and coat care: keep nails short for grip, and help groom areas your pet can no longer reach.

Introduce ramps and steps gradually with encouragement, because a hesitant pet will simply jump around an unfamiliar ramp.

Long-Term Outlook, Myths, and Questions

The long-term picture is usually reassuring. Spondylosis is a slow process, many pets never show signs, and those who do can often be kept comfortable for years with weight control, low impact activity, home adaptations, and veterinary pain management. The spurs do not disappear, but comfort and function are what matter to quality of life.

Myths and facts

• Myth: bridging spurs mean the spine is fused and the pet is crippled. Fact: many pets with extensive bridging move normally and feel fine.
• Myth: spondylosis always causes pain. Fact: it is very often an incidental finding with no clinical signs at all.
• Myth: rest is the safest approach. Fact: prolonged inactivity weakens muscle and usually worsens stiffness; controlled regular movement is generally preferred.
• Myth: cats do not get spinal problems. Fact: cats do, and they hide the signs well, so behavior changes matter.

Frequently asked questions

• Can spondylosis be reversed? The bony changes are permanent, but comfort and mobility can often be improved.
• Should I stop walking my dog? Usually the opposite; ask your veterinarian for the right type and amount of exercise.
• When is it an emergency? Sudden weakness, dragging limbs, inability to stand, loss of bladder or bowel control, or severe pain means contacting your veterinarian or an emergency clinic immediately.