Cerebellar Hypoplasia in Cats and Dogs

by | 02/24/2023

Cerebellar hypoplasia is a neurological disease that can develop in dogs or cats when the cerebellum is either not completely developed or it’s unusually small. The underdeveloped cerebellum, the part of the brain that promotes motor impulses, causes these animals to have difficulty moving normally and have poor posture, balance and coordination.

Cerebellar hypoplasia is an inherited disease, but they can also get this disorder while still in utero if the pregnant dog or cat is infected with certain infectious diseases, such as environmental toxins or herpes virus. Nutritional deficiencies can also lead to dogs or cats developing cerebellar hypoplasia.

Cerebellar Hypoplasia Presentation in Dogs

Although cerebellar hypoplasia is a genetic disease, it’s not usually noticed in dogs until they’re about six weeks old, which is the age they begin to move around more. Because the disease affects the animal’s movements, it’s hard to diagnose the animal until it begins to move around or attempt to move around freely. The main symptoms are:

  • Lack of muscle coordination
  • Tremors of the eyes and head after deliberate movements
  • Shaking in parts of the body
  • Feeling of being off balance
  • Abnormal posture

A veterinarian usually makes a diagnosis after performing a clinical and neurological examination as well as obtaining the pet’s history. They also take the dog’s breed and age into consideration when determining what kind of testing is required. In addition to blood work, a magnetic resonance imaging (MRI) test is often done to confirm the diagnosis.

The vet must use these specific examinations because there are similar diseases with similar symptoms. In order to give the best treatment, the right diagnosis must be made. In performing certain tests, veterinarians are able to rule out other diseases, such as:

  • Toxin ingestion
  • Trauma occurring either during birth or shortly thereafter
  • Meningitis and similar inflammatory diseases
  • Metabolic diseases with degenerative effects

Presentation in Cats

Cats may start showing symptoms of cerebellar hypoplasia at birth or shortly thereafter. The symptoms often progress very slowly over a couple of weeks or months. However, after that initial couple of months, the progression of symptoms ends almost completely. The actual disease is usually diagnosed at around six weeks of age, the same age as in dogs as this is when kittens start to stand on their own and walk around freely. The symptoms found in cats include:

  • Limb tremors
  • Head bobbing
  • Clumsiness or unsteadiness with a wide-based stance
  • Symptoms not present when cat is sleeping
  • Eating and movement aggravates symptoms
  • Flipping over or falling

The same strong hereditary link the disease has with dogs is not present with cats. Several factors can cause a cat to get cerebellar hypoplasia. Although the Panleukopenia virus is the most common cause of cats or dogs developing cerebellar hypoplasia, other things can also cause the disease in both animals.

  • Parvovirus – a disease that attacks rapidly dividing cells in the outer part of the cerebellum from birth and a couple weeks after that
  • The mother being severely malnourished during the pregnancy
  • The kitten suffering a physical trauma to the brain while the cerebellum is still developing

Having a cat diagnosed with cerebellar hypoplasia can be a big process. The vet will need a complete history of the cat’s health, a list of all the symptoms and any history the owner can give on the cat’s family line. Additionally, the vet will give the cat or kitten a complete physical examination, which may include the following.

  • Complete blood count
  • Blood chemical profile
  • Electrolyte panel
  • Urinalysis

The reason for all these tests is to rule out other diseases that could develop from environmental toxin damage or infections of the brain. Before the cat can be treated correctly, the vet has to be sure that the diagnosis is accurate. The most common side effect or danger to dogs with cerebellar hypoplasia is self-trauma. Due to poor balance and a wide stance, the dog could stumble and injure itself. Some severe cases of this disease result in the vet recommending euthanasia.

Breeds Commonly Affected

Cerebellar hypoplasia is a disease that can affect almost any breed of cat. The dog breeds most likely to be affected by this disease are:

  • Airedales
  • Irish Setters
  • Boston Terriers
  • Wirehaired Fox Terriers
  • Chow Chows

Fox Terriers are also affected by Dandy-Walker syndrome, which is an inherited version of cerebellar.

Treatment Options

Treatment for cerebellar hypoplasia, which is usually supportive and symptomatic, depends on the severity of the symptoms and the underlying disorder that caused the disease to develop. There is no specific effective treatment for cerebellar hypoplasia in dogs or cats. While dogs generally get worse with time, cats can lead an almost normal life.

The symptoms and programs caused by cerebellar hypoplasia do not continue as long with cats as they do with dogs. If the cat owner makes a few adjustments, the cat with cerebellar hypoplasia can lead a very good life. The cat should not be allowed to stay outside where it can encounter danger. Adjusting feeding dishes and bed in positions requiring the least movements can also make it easier for the cat to live comfortably.


Cerebellar hypoplasia has a very poor prognosis, although, the prognosis can also vary by the underlining disorder causing the disease. Different disorders are associated with cerebellar hypoplasia. If the cat or dog had a more progressive disorder that led to the disease, the disease is going to progressive much quicker with a worse prognosis. On the other hand, abnormal brain formation during fetal growth is a less progressive disorder, so animals with this disorder might have a better prognosis with cerebellar hypoplasia.

Symptoms are usually not progressive in cats and, if they live indoors, they can generally have a normal life span. Dogs with cerebellar hypoplasia tend to deteriorate as they age. The only positive thing about this disease is that it’s not contagious or painful. Owners of animals with cerebellar hypoplasia can ensure they don’t promote this disease by exercising selective breeding and only use animals whose bloodlines are free from this disease.