Feline distemper is caused by a parvovirus. This type of parvovirus can infect dogs, but they do not get sick or shed the virus post-infection.
In cats, the virus is shed in all body secretions, such as feces, urine, blood, and saliva. It can live in the environment for up to a year, so even bedding, bowls, toys, and litter boxes can be sources of infection. The highest level of viral shedding is in the cat’s feces.
Female cats that are pregnant and infected can also pass the infection to their kittens in-utero before they’re born. In pregnant cats, the infection can cause abortions, stillbirths, or neurologic conditions in the kittens.
Kittens exposed in-utero or within a week or two after birth have the most serious disease conditions, ranging from death to permanent neurologic issues or blindness. The virus can attack a kitten’s brain, specifically the cerebellum, and cause that part of the brain to not develop fully. This condition is called cerebellar hypoplasia.
Once a cat has been exposed to the virus, it replicates and spreads through the body. The virus will start to attack rapidly dividing cells in the bone marrow, intestines, and lymphatic tissue. This leads to reduced levels of white blood cells which increase the risk of secondary infections, such as viral or bacterial upper respiratory infections. While the virus attacks the lining of the intestinal tract, diarrhea and vomiting can be seen. Severe systemic infections with bacteria can also occur.
Clinical signs can vary depending on the age of the cat at the time of infection.
Since the symptoms are not specific to this virus, your vet will need to do some testing to know what’s going on. A CBC, which looks at the blood cells and platelets, is often abnormal with low white blood cell levels and low platelets. There may be an increase in the liver enzymes and a decline in the albumin level on the chemistry panel. Low albumin often indicates severe damage from the infection and these cats are at higher risk of death from the virus.
There are in-clinic tests for feline panleukopenia that test the fecal material. Even parvo tests made for dogs can detect feline infections with panleukopenia. The virus may drop to a level too low detect within 1-2 days, so it’s important to test as soon as possible after symptoms develop. Additional testing may be needed to confirm the infection.
PCR testing on blood or fecal material is another option, especially if your cat has been ill for more than a couple of days.
Serology to look for antibodies is another option. However, vaccines can affect these tests by causing the antibodies to rise, but usually not to the same extent.
There is no specific antiviral medication to cure distemper in cats. Treatment is aimed at supportive care, such as IV fluids to keep them hydrated, anti-nausea medications, antibiotics to treat secondary infections and reduce risk of septicemia, placement of a feeding tube for caloric support if not eating, and potentially blood transfusion if needed.
In kittens with neurologic symptoms, these are permanent. Most kittens are behaviorally normal, but will slightly tremor before they start to walk, may roll, have a wide-based stance, and stiff gait.
Luckily, there are multiple vaccines available to protect your cat from feline distemper. The vaccine should be given initially at 6-8 weeks of age and repeated every 3 to 4 weeks until 16 weeks of age. Then the vaccine is given at 1 year of age and every 3 years thereafter. Adult cats with unknown vaccine history should be given an initial dose, then a booster in 3-4 weeks, then 1 year later, then every 3 years thereafter.
If your cat survived an infection with feline distemper, they can shed the virus for up to 6 weeks after recovery, so be sure to keep them isolated from other cats that are not vaccinated.
You can kill the virus in the home with a 1 to 32 bleach solution (Example: 1oz bleach to 32oz of water) and let it sit for 10 minutes. Since you may not be able to treat all items with this solution, assume the virus will be present for a year indoors, and be sure all new cats are vaccinated completely before being introduced to the home.
For more information on Cerebellar Hypoplasia, including videos, please follow the link below:
Cerebellar Hypoplasia Cats are Clumsy from Birth
What You Need to Know About Vaccinating Your Cat
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