What Is Feline Cerebellar Hypoplasia?

Medically Reviewed by Amy Flowers, DVM on November 15, 2022
4 min read

A cerebellar hypoplasia cat is also known as a wobbly cat. This condition is one of the most common nervous system disorders in cats. It's caused by the underdevelopment or destruction of the cerebellum, a vital part of the brain. Although this can have many causes, the most frequent is the infection of a kitten in the womb with the feline parvovirus (also known as the feline infectious enteritis (FIE), feline distemper, and feline panleukopenia virus). Though an infection causes the condition, your cerebellar hypoplasia cat is not infectious to others. 

Feline cerebellar hypoplasia, or cat cerebellar hypoplasia, is a disorder affecting the cerebellum. The cerebellum is a part of the brain that regulates the positioning of the trunk and the strength and direction of limb movements. The cerebellum is vital for maintaining balance. It also controls the movements of the limbs, trunk, eyeballs, and head. 

Hypoplasia is the underdevelopment of the cerebellum, and it causes ataxia — incoordination, wobbliness, or unsteadiness. Cat cerebellar hypoplasia doesn't cause weakness. Your cat has the strength to walk, eat, and manage most functions but struggles with balance and coordination.

Most cerebellar hypoplasia cats are born with the condition.

You will notice these symptoms in your cerebellar hypoplasia cat: 

  • The head has a fine tremor (trembling). Unlike a cat with vestibular ataxia, the cerebellar hypoplasia cat doesn't keep their head tilted.
  • The eyes have a fine tremor. You may not notice it, but your veterinarian may find it when examining the eyes.
  • Your cat isn't weak but is uncoordinated and imbalanced. Not all cerebellar hypoplasia cats are alike. Some walk with a drunken gait (leading to the name wobbly cat), while others are unable to get around.
  • Your cat can't maintain balance while standing. You will see them using a wide-based posture. Swaying and staggering while stationary are common.
  • Feeding difficulty because their heads bob up and down. This becomes apparent at weaning.
  • Intention tremor. This trembling becomes apparent when your cat is preparing for some movement — bending down to eat or drink or grabbing a toy.

These symptoms become apparent when a kitten first stands and begins to walk. This usually happens at age 2 to 3 weeks. The symptoms of cerebellar hypoplasia are nonprogressive — they don't get worse over time. Your kitten may even get better at walking and balancing as they learn to compensate with their other senses, like vision and positional sense (proprioception).

The symptoms also depend on how much of the cerebellum is affected. If the disorder affects the entire cerebellum, the unsteadiness will be on both sides of the body (bilateral). If the cerebellar affection is partial and asymmetrical, you may see the symptoms on only one side of your cat's body.

Several types of disorders can cause cerebellar hypoplasia:

Vascular: cerebellar cerebrovascular accident

Infectious: feline infectious peritonitis, feline spongiform encephalopathy, fungal diseases, parasitic encephalomyelitis, toxoplasmosis

Anomalous: cerebellar hypoplasia (feline panleukopenia virus), intracranial intra-arachnoid cysts


Toxic: metronidazole

Brain tumors

Degenerative: lysosomal storage diseases, cerebellar abiotrophy

The most common cause is infection of a pregnant cat with the feline panleukopenia virus. This virus crosses the placenta and infects the kittens in the womb. It has a fatal effect on the rapidly dividing cells of the cerebellum. The kittens are born with hypoplasia of the cerebellum. There may be other brain defects too. All kittens in the litter may not be affected, and the affected kittens may be affected to varying degrees. The canine parvovirus causes a similar disorder in dogs. 

Vaccinating your pregnant cat with a live feline parvovirus vaccine can similarly harm the kittens. Let your vet know if your cat is pregnant when you go for vaccination.

If your cat is unsteady and wobbly, you should take them to your veterinarian. They will examine your cat and try to find out the cause. Cerebellar hypoplasia has to be differentiated from other causes of instability, like vestibular ataxia and sensory ataxia. Your vet may ask for laboratory tests or advanced imaging to find the cause. A computed tomography (CT) or magnetic resonance imaging (MRI) scan will show a small or absent cerebellum in your cerebellar hypoplasia cat.

There is no cure for this condition, but less severely affected cats make acceptable pets. The disorder can be disabling in some kittens, but some are only mildly affected. How you care for your cerebellar hypoplasia cat depends on their degree of impairment. You should take care of the usual cat needs such as nutrition, exercise, and vaccination, of course.

A cat with cerebellar hypoplasia is unable to jump and has difficulty walking on polished floors. If they're not aggressive, consider leaving their claws unclipped. This helps them walk on carpets and remain upright. Climbing becomes easier too.

There is no medication you can give your cat. Instead, you should make your home safe and helpful. If your cat tends to tumble down the last stair, placing a soft mat (landing pad) at the bottom will provide safety. Outdoor activities may be too much stimulation for your cat, but they may enjoy some time in a safe backyard.

Eating and drinking are challenging for your cat because of their head bobbing. You can help them by holding their body and head for them. A large dog bowl may make eating easier for your unsteady cat. Try to get a heavy bowl that won't topple easily.

Cerebellar hypoplasia is a nonprogressive disorder. Your cat was born with cerebellar damage, but the disorder will not get worse as they age. You may even notice that your cat gets better at walking, eating, and other functions with age. Since the disorder isn't progressive, cats with feline cerebellar hypoplasia don't die early. Your cat has the same life expectancy as other cats.