Hemivertebra

What is ... ?: 

This is a condition where there is abnormal bony development of one or more of the vertebrae - the bones that make up the spinal column. The main part of each vertebra should look like a spool when seen from the side. A hemivertebra looks like a wedge or triangle. Hemivertebra can occur in dogs that have other kinds of vertebral malformations as well. Whether the condition causes problems for the dog depends on what part of the spinal column is affected, and whether there is compression of the spinal cord.

How is ... inherited?: 
The condition is autosomal recessive in the German short-haired pointer and German shepherd. The mode of inheritance is unknown in other breeds.
What does ... mean to your dog & you?: 

A hemivertebra does not necessarily cause problems for your dog, unless it causes compression of the nerves (the spinal cord) within the spinal column. This may occur in two ways - the abnormally shaped vertebra may put pressure on the spinal cord directly, or it may be an unstable "weak link" in the vertebral column. Spinal cord compression causes back pain, weakness or inability to get up or walk, and usually requires surgery.

How is ... diagnosed?: 

Radiographs (x-rays) are necessary to diagnose hemivertebra. Your veterinarian may discover that your dog has hemivertebra while taking x-rays for another purpose. If your dog shows signs of spinal cord compression (back pain, weakness, or inability to get up or walk), special x-ray techniques (such as a myelogram) will show if the compression is caused by a hemivertebra.

How is ... treated?: 

Unless your dog has spinal cord compression, there is no need to treat hemivertebra. Where there is spinal cord compression, your dog will probably need surgery.

Breeding advice: 

It is best not to breed affected animals. Parents of affected German shepherds and German short-haired pointers are carriers of the trait and should not be bred again.
FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN.

Resources: 

Bailey CS, Morgan JP. 1992. Congenital spinal malformations. Veterinary Clinics of North America Small Animal Practice. 22(4):985-1015.

LeCouteur RA, Child G. 1995. Diseases of the spinal cord. In EJ Ettinger and EC Feldman (eds.) Textbook of Veterinary Internal Medicine, pp. 629-696. WB Saunders Co., Toronto.


What breeds are affected by ... ?
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