What is Spondylosis?

Spondylosis, also known as spondylosis deformans in dogs, is a condition where osteophytes grow on the ventral and lateral surfaces of the vertebral bodies. Osteophytes are commonly referred to as bone spurs and are bony projections that can form along joints in the body of a dog. The reason behind the formation is an increase of damaged joint surface area.

The growths are normally found by incident when the vet is examining the dog for some other reason using radiographs. Spondylosis rarely causes problems for the dogs. There spinal cord does not become compressed, but the spine will be immobilized in that particular location. In a dog with Spondylosis, bridges have formed along the ventral parts (bottom parts) of the vertebrae (the bones that make up the spine). In dogs where the spondylosis is widespread, the many bridges can weld a long row of vertebrae into a rigid, inflexible backbone.

Dogs are not the only ones who can develop spondylosis; similar growths have been found in humans, cats, bulls, and even whales.

What causes Spondylosis?

As mentioned above, bone spurs can occur when there are a lot of damaged joint surface areas, but the exact reason behind Spondylosis is not fully understood. There might be more than one genetic determinant for Spondylosis, and the diet of a dog may also play a role.

Spondylosis symptoms in dogs

A lot of dogs with diagnosed Spondylosis experience no pain at all; at least not as far as us humans can tell. If nerve roots that lead out from the cord to the peripheral nerves become encircled or pressured, spondylosis can lead to pain and suffering for the dog. In many cases, the true cause of the symptoms is however something else, such as arthritis or cauda equina syndrome. Spondylosis is easily confused with many other health problems that cause back pain.

Exactly how the Spondylosis progresses is not yet known, but it is believed to begin with the so called Sharpey’s fibres being broken down. Sharpey’s fibres are the fibres that constitute the annulus, i.e. the outer portion of the intervertebral disks. Eventually, the inner disk material will begin to protrude, which stretches the longitudinal ligament and promotes the growth of osteophytes from the vertebral bodies.

As the disease progresses, the disk spaces between the segments will bridge together. How fast this happens is mainly determined by breed and family history. It is possible for the vertebrae to fuse into a single, continuous bridge, but this is very uncommon. Another rare form of Spondylosis causes the osteophytes to grow upwards until they pinch the spinal cord.

Spondylosis treatment for dogs

As mentioned above, a lot of dogs with Spondylosis appear to suffer from no pain at all and no treatment is necessary in such cases. Your dog might experience a somewhat decreased flexibility than before, but this is seldom enough to severely decrease its quality of life.

Spondylosis often appear in older dogs that are no longer used as herding dogs, breeding dogs etcetera, and they can therefore live out the rest of their lives without the decreased mobility causing any significant problems for them. The same is naturally true for dogs kept solely as companions.

In some dogs, the Spondylosis will unfortunately become much worse within a short period of time, instead of slowly progressing. This might be caused by trauma, since trauma can make the bridge in the spine fracture.  

Skeletal and muscular disorders in dogs: (click for more info)
Canine hip dysplasia
Congenital vertebral anomalies in dogs
Craniomandibular osteopathy in dogs
Elbow dysplasia in dogs
Hypertrophic Osteodystrophy in dogs
Hypertrophic Osteopathy in dogs
Legg-Calvé-Perthes syndrome in dogs
Luxating patella in dogs
Masticatory muscle myositis in dogs
Masticatory Muscle Myositis (MMM) and Extraocular Myositis (EOM) in dogs
Osteoarthritis in dogs
Osteochondritis Dissecans in dogs
Panosteitis in dogs
Spondylosis in dogs