When people meet Sophie for the first time, the first question they usually ask is something like, “What’s the matter with her legs?”, “Why does she walk funny?”, or “What’s wrong with her?” After I explain that she has cerebellar hypoplasia (CH) and what that means, the next common question asked is, “What causes cerebellar hypoplasia?” While CH can be caused by a few different things, the most common cause is panleukopenia.
What is Panleukopenia?
Feline Panleukopenia, also known feline distemper or feline parvo, is a viral infection contracted by the feline parvovirus (FPV). This virus infects and kills cells that are rapidly growing and dividing, such as those in the bone marrow, intestines, lymph nodes, and a developing fetus. FPV also attacks a cat’s white blood cells, compromising the immune system. Symptoms include bloody diarrhea, severe dehydration, malnutrition, anemia, lethargy, loss of appetite, fever, vomiting, and often death.
Panleukopenia is a highly contagious disease. It is spread through contact with an infected cat’s bodily fluids and feces, as well as by fleas. While an infected cat may only shed the virus for 1-2 days, the virus is extremely resilient and can survive for longer than one year in a suitable environment. Holy cow! This means that a cat may become infected without actually coming into direct contact with an infected cat – like through bedding, cages, food dishes, and the hands or clothing of people who handle the infected cat.
How does Panleukopenia Cause Cerebellar Hypoplasia?
As mentioned above, FPV infects and kills cells that are rapidly growing and dividing, such as those in a developing kitten in utero. If a pregnant mother cat contracts the virus or is vaccinated against FPV while pregnant, the virus may attack the kittens’ cerebellum. This attack on the cerebellum may prevent it from fully developing before birth, resulting in cerebellar hypoplasia.
The cerebellum is the part of the brain that is responsible for motor control and coordination. Having an underdeveloped cerebellum results in jerky movements, uncoordinated motion, and tremors. (This is why cats with CH are affectionately known as “Wobbly Cats.”)
The outcome of a litter of kittens by an infected mother can vary. If the mother contracts FPV early on in her pregnancy, the kittens will most likely be aborted. If she contracts the virus later on in pregnancy, some of the kittens may be born with CH, and some may be “normal.” Multiple CH kittens within one litter can even be born with varying degrees of severity.
What are Other Causes of Cerebellar Hypoplasia?
The cerebellum is a delicate part of the brain that continues to develop right up until birth. This means that any sort of trauma to the unborn kittens in utero can affect their brain development. While panleukopenia is the most common cause of cerebellar hypoplasia, malnutrition, poisoning, or physical trauma to the mother and/or kittens may result in the kittens being born with CH.
I will stress that all of these causes are things that occur while the kittens are in the womb. A cat cannot contract or develop CH later in life.
How Can Cerebellar Hypoplasia Be Prevented?
1. Vaccinate against panleukopenia. The FPV vaccine is a core vaccine given to kittens. Once a cat has reached adulthood, he/she can get the booster shot every 1-3 years.
2. Since CH can be caused by a mother cat being vaccinated for FPV during pregnancy, make sure that you do not vaccinate if you suspect your cat may be pregnant. Mention your concerns to your veterinarian, who can then determine for sure whether or not your cat is pregnant.
3. If you have a mother cat in your care, keep her in a safe place away from possible toxins and poisons to reduce any potential harm to her and the unborn kittens. If she’s an outdoor cat, try to temporarily bring her inside or build a makeshift shelter for her outside. Keep watch over her.
And last, but certainly not least…
Spay and neuter your cats!