All About Hemivertebra in Brachycephalic Dogs

Written and verified by the veterinarian and zootechnician Sebastian Ramirez Ocampo

Last update: 23 August, 2023

Due to their anatomical characteristics, brachycephalic dogs are predisposed to suffer a series of specific pathologies throughout their lives. One of the most relevant is the hemivertebra, a congenital malformation that affects the welfare of pets that suffer from it.

Considering that breeds such as the bulldog have become very popular in recent years, it’s important for people to get to know all aspects related to one of the most prevalent skeletal disorders in this type of dog. For this reason, we’re going to tell you all about the origin, symptoms, diagnosis, and possible treatment of hemivertebra in brachycephalic dogs. Don’t miss it!

What are brachycephalic dogs?

They’re dogs with well-defined and distinctive physical features. Among the most outstanding characteristics are the following:

• A circular skull
• Short or flattened muzzle
• Narrow nostrils
• Bulging eyes
• Soft and elongated palate
• Solid bodies and short limbs
• Curled tail

Although these attributes are noticeable in some breeds, the reality is that there’s scientific evidence that many of these anatomical peculiarities predispose to the appearance of intermuscular, respiratory, cardiac, ocular and digestive diseases.

In an effort to achieve these types of characteristics in dogs, breeders have used harmful reproductive selection techniques such as inbreeding; that is, crossing close relatives.

In fact, according to a study published in the journal Frontiers in Veterinary Science, brachycephalic dogs are 3.3 times more likely to give birth to neonates with congenital malformations than dogs of other types of breeds. Of these anomalies, the hemivertebra is one of the most common and of greater importance in the area of veterinary medicine.

What is hemivertebra?

A hemivertebra is the deformation of one or more of the vertebral bodies that compose the spine. To be more precise, the vertebra presents an incomplete formation or absence of a part, which leads it to acquire a wedge or triangle shape.

It usually appears in the thoracic area, and depending on its conformation, it can cause a dorsal or lateral curvature of the spine. That is, kyphosis or scoliosis.

Its origin is embryonic, as it develops during the early stages of neonatal growth. It is suggested that it is caused by problems of vascularization or ossification of the vertebrae during this stage, which generates the malformation of the vertebrae.

Although it can appear in any type of dog, brachycephalic breeds are more predisposed due to the heritability of recessive genes resulting from inbreeding.

Symptoms of hemivertebrae in dogs

Due to the anatomical conformation of the hemivertebra, in most cases, direct pressure is generated on the spinal cord. Therefore, the clinical signs are similar to those produced by neurological damage.

Accordingly, symptoms include:

• Pain on palpation
• Ataxia
• Weakness or paralysis of the hind limbs
• Fecal and urinary incontinence (in more severe cases)

In addition, when there’s kyphosis in the spine, other problems such as degeneration or herniation of the intervertebral disc can be generated. These clinical manifestations begin very early, usually between 4 to 10 months of age.

However, it’s important to note that not all dogs with hemivertebrae develop this type of neurological symptomatology. That’s to say, some live with this malformation all their lives without neurological signs.

However, according to a study shared in the journal Veterinary Radiology & Ultrasound, within the brachycephalics, the pug is 10 times more likely to develop neurological signs when suffering from hemivertebra than other breeds such as the French bulldog or the English bulldog.

Diagnosis

The diagnosis of this pathology is based on a physical examination of the patient and on the evaluation of the anamnesis. In addition, it’s important to complement it with the use of diagnostic imaging such as lateral and dorsoventral radiographs.

If possible, computed tomography (CT) and magnetic resonance imaging (MRI) are recommended to identify the extent of the lesion on the spinal cord.

Treatment

The only resolution of this pathology is surgical intervention. However, it is only recommended in cases in which the spinal cord is involved.

Surgeries aim to decompress and stabilize the spine, using techniques such as laminectomy or hemilaminectomy and the use of screws or threaded pins to fix the spine.

In most cases, dogs who undergo these interventions report a satisfactory recovery. However, it’s also reported that some show chronic complications, However, these are of minor relevance, such as pain and swelling.

Finally, it’s advisable to identify this type of malformation at an early age, because as time goes by, the approach becomes more complicated.

In summary

As you can tell, hemivertebra is a pathology that puts pets’ health at risk. Above all, it affects brachycephalic breeds, which are popular nowadays.

Although the objective isn’t to condemn people who acquire them, it is important that you ask yourself if you’re prepared to deal with the diseases that accompany this type of dog. If this isn’t the case, then it’s best to adopt or buy dogs that don’t have so many degrees of inbreeding.

Finally, if your dog suffers from hemivertebra, we would encourage you not to breed them. In this way, the genes causing the disease won’t be transmitted to the following generations.