Hemivertebrae – The Spine Deformity In Flat-Faced Dogs
French bulldog hemivertebraeIt’s hard to resist the sweet face of a French bulldog, Pug, English bulldog, Boston terrier or Boxer. Their adorable flat-head, short-nose and corkscrew tails are the epitome of doggie cuteness. But did you know that from the tip of their little nose to the end of their tiny tail, each of these breeds has a skeletal deformity called Hemivertebrae?
Hemivertebrae is a congenital abnormality of the spine where the left and right halves of the vertebrae grow unequally to create a “butterfly” shape in what should otherwise be a very straight spine. The condition causes the spine to bend and twist or grow at an angle and fuse vertebrae together into a wedge.
Here’s a hemivertebrae spine on the left and a normal spine on the right.
While this might sound like an awful condition for a dog, Hemivertebrae is NOT considered a medical problem, especially if it only occurs in the tail. The deformity is actually a desired characteristic in brachycephalic breeds (dogs with a flat-face and short-nose) because it is responsible for the adorable appearance of these dogs. Typical canines have 49 to 53 vertebrae, depending on the length of their tail. Dogs with screw tails have 10 to 15 less vertebrae.
With that said, Hemivertebrae can be a painful condition for puppies during the first 9 months of life while their spine is still growing. And the deformity can turn into a serious health issue if the amount of twisting and bending of the backbone starts to put too much pressure on the spinal cord.
A compressed spinal cord can lead to a wide range of problems, depending which part of the spine is affected. Dogs with even a moderate twist or compression can show signs of:
If your brachycephalic breed dog demonstrates any of these symptoms they should be seen immediately by a veterinarian because the longer the nerve supply is compressed, the greater the chance of permanent damage. A veterinarian can confirm the condition with an x-ray and may follow-up with a CT scan, MRI or myelogram to detect how badly the spinal cord is compressed.
Some dogs respond well to rest and an injection of corticosteroid to reduce the inflammation that is causing the compression. Other dogs with a more severe spinal compression require surgery to fix the problem.
When this happens, a surgical procedure called a Hemilaminectomy is performed to remove the disc material that is cutting off the flow of blood to the nerve.
Boston terrier hemivertebraeThe good news is that most dogs recover from a spinal cord compression, but the ultimate outcome depends entirely on the severity of the problem. The best way to prevent a compression due to Hemivertebrae is through responsible breeding of flat-nose, flat-face dogs. A responsible breeder will work hard to keep the condition from becoming too extreme.