Spondylosis Deformans

In some dogs and cats, bone spurs form on the vertebrae. Sometimes those spurs might even grow to bridge the gap between two adjacent vertebrae. This condition of the spine is called spondylosis deformans. The cause is unknown, and it occurs much less frequently in the feline population, compared to the canine population. Most pets that experience the condition have no signs, but some might become lame, appear stiff, or suffer obvious back pain. In those cases, exercise restriction, weight loss, anti-inflammatory drugs, or other pain relievers can help.


Spondylosis deformans (or spondylosis, as most veterinarians refer to it) is a degenerative process of the spine in which bone spurs (osteophytes) form at the edges of the vertebrae. Sometimes, these may even coalesce into bony bridges between the vertebral segments of the spine.

The lower back is most often affected, especially the lower thoracic and lower lumbar vertebrae.

The cause of this common canine condition is unknown, but intervertebral disc disease (“slipped” discs), trauma to the spine, and congenital deformities have all been associated with it. Nonetheless, true spondylosis deformans is considered idiopathic, meaning that the cause is not known.

Middle-aged to older animals and bigger-breed dogs are predisposed. Though dogs are more likely candidates for this condition, cats can suffer from it, too.

Symptoms and Identification

In most cases, the condition sounds more painful than it actually is. In fact, most dogs and cats who experience spondylosis deformans are asymptomatic, meaning that they appear to have no signs. (In animal medicine, however, it’s important to note that our human perception of pain may inadequately represent the true state of our pets’ feelings.)

In pets that do show signs, lameness (limping), back pain, stiffness, and loss of muscle mass over the affected areas are the most common, especially after exercise. Spondylosis deformans rarely leads to neurological signs, and in most cases, it is because something else is causing compression on the nerves.

In any case, spondylosis deformans is almost always diagnosed with radiographs (x-rays). A CT scan and/or myelogram (a dye-based study of the spinal canal) are often used to diagnose spinal cord compression if it’s suspected, but again, it is usually not caused by the spondylosis itself.

Affected Breeds

Some studies suggest that Boxers are the most common breed affected, with other large-breed dogs (such as German Shepherds and Airedale Terriers) following. Nonetheless, this area of study is not without controversy. Veterinary radiologists posit that smaller breeds, such as Cocker Spaniels and Dachshunds, may be as likely to suffer spondylosis deformans.


The treatment of spondylosis deformans depends on the degree of back pain, lameness, stiffness, or loss of muscle mass the patient experiences. Exercise restriction, weight loss, and pet-specific anti-inflammatory medications (either NSAIDs or corticosteroids) are typical treatments.


Genetic predisposition to spondylosis deformans is suspected in some breeds, though this has not been established. Modes of prevention, therefore, are speculative.

This article has been reviewed by a Veterinarian.

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