Overview
Vertebral malformation is a condition some dogs and cats are born with, where parts of their spine don’t develop quite the way they should. Instead of forming long, evenly shaped bones, one or more of the vertebrae may become malformed.
Because of their unusual shape, these bones don’t always line up properly with the rest of the spine. Over time, this misalignment can lead to twisting or instability in the spinal column. In some cases, it puts pressure on the spinal cord or nearby nerves, causing neurological dysfunction. Not all animals with vertebral malformations show signs of a problem, but for those who do, early diagnosis and appropriate care can make a big difference.
Some common types of vertebral malformations include hemivertebrae, block vertebrae, butterfly vertebrae and spina bifida.
Causes
Vertebral malformations are usually congenital, which means they’re present at birth. These changes in the shape or structure of the spine happen during early development while the puppy is still growing in the womb. Genetics and selective breeding are believed to play a significant role, as these malformations are more common in certain breeds—particularly those with screw tails, such as French Bulldogs, English Bulldogs, Pugs, and Manx cats.
Clinical Signs
While some pets with vertebral malformations may live their whole lives without any symptoms, others show signs especially as they grow or become more active. The severity and type of symptoms depend on where in the spine the malformation is located and how much pressure it puts on the spinal cord or nerves.
If the spinal cord is compressed, it can lead to a range of neurological problems, including an arched back, pain, weakness, difficulty walking, or even complete loss of function in the back legs. Some dogs may also lose control over their bladder or bowels.
Diagnosis
In many cases, vertebral malformations are found incidentally during routine X-rays. However, their presence doesn’t always mean they are causing—or will cause—neurological problems. MRI is the most useful diagnostic tool for evaluating this condition. Unlike X-rays, MRI allows us to visualize the spinal cord itself and assess for any compression or damage. It also helps rule out other, more common causes of neurological signs, such as intervertebral disc disease.
Treatment
Treatment for vertebral malformations depends on how severe the condition is and whether the spinal cord is being affected. Many patients, especially those with mild changes, never need treatment and can live full, happy lives with just regular check-ups.
However, if the spinal malformation is causing pain or neurological symptoms like weakness or wobbliness, treatment may be needed to keep your dog comfortable and mobile.
Treatment options include medical management for animals with mild to moderate symptoms. This treatment often involves pain management, anti-inflammatory medications and physical therapy. Surgical interventions are reserved for more severe cases and may be considered to relieve the pressure. While the malformed vertebrae can’t be “replaced,” the spine can be stabilized and part of the bone removed to reduce compression. This is typically a salvage procedure and only pursued when quality of life is seriously affected. With or without surgery, the primary goal of treatment is often not full recovery, but rather managing symptoms, preserving mobility, and ensuring your pet remains comfortable with a good quality of life.
Prognosis
The outlook for animals with vertebral malformations can vary widely. Some dogs with mild cases respond well to medications and physical therapy, living comfortable lives without major limitations. While not every pet will regain full strength or function, treatment often leads to significant improvements in mobility, comfort, and overall quality of life. However, if the spinal cord is severely compressed, clinical signs may continue to progress despite appropriate treatment.