Spondylosis deformans is a condition that affects the vertebral bones of the spine. It is characterized by the presence of bone spurs or osteophytes (bony prominences) along the edges of the bones of the spine. A bone spur or osteophyte may develop in a single spot on the spine, or there can be multiple bone spurs in several different locations along the spine (more common). The most common places that spondylosis deformans lesions develop are along the thoracic vertebrae (upper back), especially at the thoracolumbar junction between the rib cage and the abdomen, in the lumbar spine (lower back), and in the lumbosacral spine (where the lumbar spine meets the pelvis). In some cases, the bone spurs may become large enough that they appear to form a complete bridge between adjacent vertebral bones. This is sometimes called “bridging spondylosis”.
Spondylosis deformans is a chronic condition that is associated with aging or excessive motion at the spine. Research indicates that it often develops as a secondary problem related to degenerative disease of the intervertebral discs that sit between each spinal vertebra. In the normal spine, the vertebral bones are joined by ligaments to form a flexible protective column around the spinal cord. The intervertebral disc between each vertebral bone acts as a shock absorber or cushion, and the series of joints that make up the spine give the back flexibility of motion while also protecting the delicate spinal cord from damage. Spondylosis causes a decrease in mobility and stiffness through the spine.
Many dogs with spondylosis deformans are free of any symptoms. Sometimes, the bone spurs restrict the movement of the spine and the dog may appear to be stiff or less flexible in the back. If a bone spur grows near a nerve root as it comes out of the spinal canal, it may put pressure on the nerve, causing pain or lameness. If the condition is painful, the dog may whine or cry when touched along affected areas of the back.
Spondylosis deformans is usually diagnosed from radiographs (x-rays) of the spine that are performed at our practice. In some cases, it may be an incidental finding that is noticed when radiographs are taken for some other reason. Since there is no difference in the radiographic appearance of a bone spur that results from spondylosis deformans and one that results from an inflammatory lesion, multiple radiographs may be needed to thoroughly assess the spine and identify radiographic patterns that indicate other causes of instability. This is especially important if the dog is showing any symptoms of nerve damage or appears to be in pain. Other diagnostics that may be recommended include a myelogram (where a special dye is injected into the spinal fluid surrounding the spinal cord, followed by radiographs) and/or magnetic resonance imaging (MRI). In some cases, your veterinarian may recommend referral to a neurologist for further diagnostics and/or treatment.
Many dogs with spondylosis deformans appear to be pain-free, and in these cases treatment is not always necessary. If the pet appears to be painful, non-steroidal anti-inflammatory drugs (NSAIDs) or other analgesics may provide relief. Physical therapy, weight loss, and controlled exercise programs may be helpful in some cases. Modalities that treat pain and inflammation such as laser, ultrasound, shockwave, and TENS can also be useful. Some dogs that develop secondary tension in the muscles surrounding the spine may benefit from heat, massage, stretching, and acupuncture. In rare cases, the osteophytes can cause spinal cord compression, and in these cases surgery to remove them may be indicated.
