Chris Kouwenhoven

Feline panleukopenia

Although today's subject is not seen as often as in the past, primarily due to the widespread availability of highly effective vaccines, it is still something we see because there are so many unvaccinated cats. This highly contagious and often fatal disease is caused by a parvovirus that is closely related to the canine parvovirus type 2.

The virus attacks and destroys actively dividing cells such as those found in the bone marrow, intestinal epithelium (the layer closest to the inside) and lymphoid tissues. In very young animals, which are the most susceptible to the virus, the cerebellum of the brain and the retina of the eye are most frequently involved. Since the cerebellum is responsible for fine motor coordination, when it is damaged by the virus we often see incoordination and tremor in affected kittens and young cats. In pregnant queens, the growing fetus is a prime target, resulting in fetal death, mummification of the fetus, abortion, and stillborn kittens. Vaccinated queens provide passive immunity to their kittens during nursing. We must still vaccinate these kittens, once they are weaned, since the passive immunity they get from the queen is only temporary.

Transmission of the virus is through the nose and mouth from secretions of infected cats during the acute stage of the disease. The virus is very resistant to inactivation and may even be shed in the feces of recovered cats for as long as 4-6 weeks. Fomites (inanimate objects such as shoes, water and food bowls etc.) can also be the source of the infective virus. It can be destroyed using a 6% chlorine bleach solution.

Many cases are subclinical and we may not even be aware of the infection. However, the illness may be obvious and fatal within 5-7 days, especially in kittens or young adults up to a year of age. Symptoms include fever of 104-107 degrees, often followed by vomiting a few days later. Diarrhea may be seen within a few days after the vomiting. Dehydration and severe depression quickly follows. In most kittens death occurs before tremors and incoordination can develop, but some initial survivors may exhibit these symptoms. The outlook for these kittens is grave and most will end up being euthanized since the cerebellar damage is irreversible. A mortality rate ranging from 25 to 90% can be expected.

Cats with feline panleukopenia can be treated; however, it is something that will require close monitoring and aggressive re-hydration and electrolyte monitoring that only your veterinarian can provide. The best course of action, of course, is to vaccinate your kittens at about 8-10 weeks of age and again at 12-14 months of age. Annual vaccinations should also be administered. Even strictly indoor cats should be vaccinated because of the possible transmission via fomites when owners come in contact with infected cats outside the home. Cats adopted as adults should also be vaccinated at once because we can not be sure of their immune status.