Hemivertebra in Dogs

Hemivertebra in dogs is a congenital condition where your dog has one or more vertebrae that are deformed; the vertebra may be fused or wedge-shaped leading to twisting in the spine. While each vertebra will usually look like a spool when looked at from the side, when a dog has a hemivertebra it will look like a wedge or a triangle. 

The condition may or may not cause issues for the dog; it will depend upon the part of the spinal column that is impacted, whether the spinal cord is being compressed or if the condition causes a weak place in the spinal column. Should your dog experience compression on his spinal cord, he may experience pain, weakness, or be unable to walk. In these cases, surgery will likely be necessary.

If your dog is experiencing hemivertebra of the tail it will not be an issue. Should it be present in other parts of his spine it can lead to your dog experiencing significant problems.

A congenital condition, hemivertebra leads to a fusing or twisting in the dog’s spine. While some may not experience symptoms as a result, others may experience pain, weakness or the inability to walk.

The symptoms that your dog experiences as a result of hemivertebra are dependent upon which vertebrae and how many, are deformed. 

When hemivertebra is present in your dog’s tail, it typically is not an issue. When it is in his spine it can lead to serious problems. The deformity of the vertebrae will lead to a twisting of the spine which can compress your dog’s spinal cord. Should this occur, you may see the following:

• Weakness in his hind limbs
• Urinary and/or fecal incontinence
• Pain

The symptoms your dog experiences will worsen as he grows, leveling off at around nine months of age when his spine stops growing.

Types 

Hemivertebra can be minor, where only one or two vertebrae have the deformity and the dog does not experience any clinical signs. In some cases, the dog will experience minor symptoms; in other cases, the condition will significantly impact the dog’s ability to function.

Hemivertebra is a congenital condition. Breeds that have been bred specifically to have “screw tails” (English Bulldog, French Bulldog, Pug, Boston Terrier) are susceptible to the condition. German Shorthair Pointers and German Shepherds can experience this condition as a result of inheriting an autosomal recessive trait. It is not known how the condition is inherited in other breeds.

Should your dog not be experiencing symptoms as a result of hemivertebra, the condition may only be discovered when he is having x-rays for another reason. If you are noticing any pain or weakness in your dog, or if he is unable to walk, your veterinarian will conduct a physical examination and will likely then have x-rays done. Special x-ray techniques like myelograms can be used to show any compression of the spine occurring as a result of the hemivertebra. CT scans and MRIs are other ways to determine if the spinal cord is being compressed.

Treatment will not be necessary unless your dog is experiencing spinal cord compression as a result of hemivertebra. Should the impact on your dog be minimal, rest and anti-inflammatories may be sufficient treatment. If the compression is more significant, surgery is usually necessary to resolve the compression being experienced. The surgical procedure is called a hemilaminectomy, which is when the material of the disc that is pressing against the spinal cord is removed. The spine will then be stabilized.

Your dog’s recovery from hemivertebra will depend upon how severe his condition is. Some dogs just have one or two vertebrae that are abnormal and will experience no clinical signs, while others will have many abnormal vertebrae which will lead to severe symptoms. Should your dog require surgery, it is usually successful and in the majority of cases, the dog will regain the ability to walk. 

It is important that you work closely with your veterinarian regarding your dog’s recovery from surgical treatment. You will want to attend follow up appointments as recommended so that your veterinarian can check on your dog’s progress and make any changes to his treatment as necessary.