Dog Health: Cervical Vertebral Instability

Cervical vertebral malformation (CVM)is one of the most common causes of "wobbler" syndrome which occurs in both in young, rapidly growing dogs and old dogs. This category not only includes malformation of the bones and joints of the cervical vertebrae (which can be exacerbated by high-protein diet) but also degenerative changes in joints. Two subdivisions of cervical vertebral malformation exist: Cervical static stenosis (CSS) is a narrowing of the vertebral canal that persists throughout the range of neck movements. Cervical vertebral instability, on the other hand, results in a dynamic stenosis, compressing the spinal cord only when the neck is flexed and is caused by the instability of the intervertebral discs of the neck. The midcervical (C3-C4 to C5-C6) vertebrae are involved and exhibit several types of malformation.

Breeds at Risk

This condition has been reported in many dog breeds but is most common in the Great Dane, Doberman Pinscher (usually older than 2 years of age) and Boxer.

Signs of Cervical Vertebral Instability

Common clinical signs include lack of muscle coordination (ataxia), weakness and paralysis. The degree of spinal cord compression varies and is attributed to a combination of abnormal vertebral development and degenerative changes secondary to instability.

Ataxia can be present in all four limbs, although the pelvic limbs seem to be affected to a greater extent which results in wobbly, unsure gait.

Diagnosis of Cervical Vertebral Instability

The condition is usually diagnosed through observation of the dog's gait, various types of neurological testing, and the use of plain X-rays or myelograms.

Treatment of Cervical Vertebral Instability

The standard conventional treatment for this progressive condition is steroid therapy, rest and neck bracing to immobilize the weakened joint. Surgery may be used to decompress the spinal cord and stabilize the effected joint; however, its success rate is not high and the dog could be further impaired after surgery. Surgery is performed only after performing a myelogram.

References:
1. Radiographic Interpretation for the Small Animal Clinician By Jerry M. Owens, Darryl N.
2. Anti-Aging for Dogs: A Longevity Program for Man's Best Friend By John M. Simon