What is cerebellar hypoplasia?

Cerebellar hypoplasia (CH) is a developmental condition in which the part of the brain that controls movement, balance and coordination fails to develop properly. Although it occurs in many animals, it is most commonly seen in cat and dogs. In cats, the syndrome is also known as "wobbly cat syndrome", "drunken kitty syndrome", or "bobble-head kitty syndrome".

CH is not infectious or painful.

Causes

In cats, CH usually occurs when a pregnant cat is infected with feline panleukopenia (AKA parvo or distemper or FPLV) and passes the infection to her unborn kittens. This can happen when the mother is actively infected with the virus or when the mother is given a distemper vaccine while pregnant. One kitten or the entire litter can be affected with CH. In addition, vaccinating kittens for distemper too early can result in CH.

Puppies can also develop CH this way, but the most common way puppies develop CH is surviving parvo within the first few weeks of being born.

Other possible causes of developmental CH include the following.

• Hypoxia (low blood oxygen)
• Malnutrition
• Fungal infection
• Protozoal infection
• Viral infection
• Rickettsial infection (from ticks, fleas, mites, lice)
• Traumatic brain injury

Symptoms

Puppies usually display symptoms as soon as they try to walk. This may be the case for kittens as well but, usually, they are symptomatic at birth. Kittens may have difficulty getting to their mother to nurse or problems suckling or swallowing.

They may roll around while the rest of the litter are starting to stand and/or walk. As they become more mobile and try to stand or walk, they may display jerky movements, tremors, swerving, head bobbing, chicken-pecking at food, or falling. Some may never be able to walk, eat, or drink on their own.

Severity of the symptoms depends on the severity of CH. The most common symptoms include the following.

• Head tremors
• Jerky or uncoordinated walking
• Lack of balance
• Wide stance
• Incorrect vocalization
• Involuntary, rapid eye movement
• Decreased muscle tone

Diagnosis

CH cannot be detected using routine laboratory tests so animals are generally diagnosed based on symptoms. However some symptoms mimic other health issues so tests should be administered to rule out other causes for the symptoms.

The severity of the symptoms depends on how much of the cerebellum was affected and at what stage in its development the infection occurred.

Prognosis

Unfortunately, there is no cure for CH and the condition is permanent. However the symptoms should not worsen over time and cats and dogs with CH will eventually adapt to their disability and, with extra-tender loving care, can have a normal life expectancy.

• They should be spayed or neutered and vaccinated when old enough.
• They cannot be declawed as they require their claws for traction.
• They must be kept indoors because they could easily be injured or attacked if they go outdoors.
• If their symptoms are pronounced, their homes may require special modifications.

Degrees of Severity

MILD
Animals with mild CH are very capable. They require little to no extra care, although some modifications to the living area may be helpful.

• Unusual gait, a high step, or waddle.
• Occasional balance loss.
• Subtle head tremors when focused, excited, or stressed.
• Able to walk, run, jump, and climb.

     Useful Modifications/Supplies

1. Carpet/rugs to provide traction.
2. Pool noodles or pipe insulation tubes to pad wall corners and furniture edges.
   
3. Foam floor tiles to provide traction and line flat vertical surfaces.
4. "Baby" gates to block stairs.

MODERATE
Animals with moderate CH can get around without help. The tail and head ends of the body may appear to be doing different things. A modified living area may be necessary to prevent injuries from falls. Some assistance in accomplishing essential tasks may be helpful or necessary.

• Noticeable head tremors, especially when focused, excited, or stressed.
• Frequent loss of balance.
• Frequent falls.
• Legs splayed in a wide stance when walking.
• "Bunny hopping" with the back legs when running.
• Usually able to climb but claws required to latch on a pull up.

     Useful Modifications/Supplies

1. All modifications listed above.
2. Nets for banisters to prevent squeezing between railing and falling.
3. Pillows to pad beside beds, chairs, etc (they jump off in a very ungraceful manner).
4. Towels on climbing items to make them easier to climb.
5. Ramps with grip strips
6. Elevated food bowls (they sometimes fall forward if they lean too far).
7. Litter box with high sides (they lean against the sides to support themselves while using the box).

SEVERE
Animals with severe CH cannot stand up or walk without help. Significant modifications to the living area are required to prevent injuries and to accomplish essential tasks.

• May flip and flop to get around.
• May move around by latching onto fabric/carpet with claws and pulling.
• Constant head tremors.
• May not be able to get to or use a litter box and may require bladder to be manually expressed.

     Useful Modifications/Supplies

1. All modifications listed above.
2. Newspaper or pee pads. They cannot use the litter box and may need to lay down to go to the bathroom.
3. Playpen to provide a soft, confined area when left alone. They cannot be left alone on furniture even for a moment as they will likely fall off and land on their heads, which can cause seizures over time.
4. Silicone adjustable-height food and water bowls. It is crucial that they not lean forward too far when drinking water if they have severe head tremors.
5. Waterproof covers for furniture, etc. They will have bathroom accidents.
6. Extra towels/blankets.
7. LOTS of baby wipes to clean them as they likely won't be able to clean themselves.
8. Dry shampoo as a bath may bee needed several days in a row and a wet bath will remove the essentials oils from their fur.
9. Ear cleaner which they will need at least biweekly as their ears will get dirty because they are laying down all the time.
10. Eating and drinking must be supervised; otherwise they may choke or drown.

Does your cat or dog have CH?

You can complete the screening form here to help determine whether your cat or dog has cerebellar hypoplasia.