A hemivertibra, also known as hemi-vertibrae or simply hemi-vertibra, is a deformity of the spine that often manifests itself at a very early age, frequently before the age of six months. The front and rear borders of each of the numerous vertebrae that make up the spine are typically aligned in a parallel fashion with one another. One or more of the afflicted dog’s vertebrae are fashioned like a wedge, rather than being parallel to one another. The French and English Bulldogs, the Boston Terrier, and the Pug are the breeds most likely to be affected by this illness. Other breeds that are more likely to be affected include the Boston Terrier. There may be simply one vertebra that is malformed, or there may be numerous vertebrae that are deformed. It is possible for there to be no accompanying neurologic effect, but it is also possible for it to create disorganized movement of the back limbs, partial or complete paralysis depending on the degree of spinal cord compression that has occurred.
When the dog is between 6 and 12 months old, the abnormally shaped vertebra begins to interfere with the nerves that run through them, which are responsible for regulating the dog’s hindquarters. The newborn puppy is not as severely impacted by this condition. After that, these pups either start to stumbling about or entirely lose the ability to walk. Some people remain paralyzed for life, while others see some improvement in their condition as a result of receiving acupuncture treatments. This is virtually invariably an issue that ends in death, with the level of pain and dysfunction becoming more severe over time.
There have also been reports of instances in which adult canines have been afflicted with Hemivertibra (HV). It is possible that the dog’s spine was injured in an accident rather than having a fault from birth, or the misalignment of the spine may be extremely minor. However, it is more likely that the dog was born with the deformity.
It seems that there has been an increase in the number of pugs affected with HV in recent years. Even though the X-rays of the parents show that they have healthy vertebrae, they may still be able to have pups that are infected with HV. It seems that this style of inheritance is polygenic and threshold, which means that it will require a significant amount of time, effort, and research to discover the root of the issue and have a handle on how to start fixing it. In the meanwhile, many breeders are voluntarily eliminating from their breeding programs any sires or dams that have produced HV pups. This is being done to protect the health of future generations. There are some breeders who are going one step further and x-raying each puppy before it is sent to its new family. A registry has been formed for the French Bulldog breed in order to assist breeders in becoming aware of those dogs who have satisfactory x-rays for the condition known as HemiVertibra. This link will take you to an excellent website that discusses the issue in French Bulldogs, who are structurally quite similar to Pugs. This link will also take you to a page that has a companion article on invertebral disk illness.
If you think your Pug is exhibiting symptoms of developing paralysis in the rear end or increased discomfort while moving, please make an appointment to visit your veterinarian as soon as you possibly can!