Feline panleukopenia, or feline distemper, is a highly contagious viral disease. Confusion surrounds this disease because of its name. It is not, as some think, related to canine distemper, which causes coldlike symptoms followed by seizures. Feline distemper causes fever, loss of appetite, vomiting, depression, diarrhea, dehydration and other complications that frequently result in death.

Feline panleukopenia is caused by feline parvovirus. Transmission occurs readily through contact with infected cats or infectious saliva, urine, feces and other discharges. The virus may remain infective in the environment for many months. Most common disinfectants have little effect on it.

In the past, feline panleukopenia killed thousands of cats every year. Because as many as 90 to 100 percent of unvaccinated cats exposed to feline distemper will become ill, and many of them, especially the very young and the very old, will die, this disease used to decimate entire neighborhoods of cats. Vaccination has limited this disease greatly, but it is still a threat to unvaccinated cats and kittens.

Most veterinarians use combination vaccines that protect against feline upper respiratory diseases as well as feline panleukopenia. Vaccination boosters should be given according to vaccine label instructions; usually every two to four weeks until a kitten is at least 12 weeks old, with a minimum of two boosters given during this period. Thereafter, annual boosters maintain immunity.