Feline Infectious Peritonitis (FIP) is caused by a particular coronavirus that mutates
in some cats to become disease-causing. Diagnosis of this virus is particularly tricky, because the test only verifies
exposure to any coronavirus, including ones that only affect dogs, pigs, etc. A positive test means that the cat has
been exposed to some coronavirus and 1) will never show any signs of illness, eventually converting to negative
status, 2) will never show signs of the illness but become a chronic or intermittent shedder of the virus, or 3) mutate
the virus into FIP- causing organism and become sick with either the wet or dry form of the virus.
Signs of disease in an FIP infected cat can be classified as 1 of 2 types: wet
or dry. Both forms are eventually fatal, usually within a few weeks or months. The wet form causes abdominal
distension (due to accumulation of a yellow, viscous fluid in the abdomen), kidney disease, weight loss, and/or diarrhea OR
thoracic disease due to fluid accumulation in the lungs. Organs in one or both caviies may have grainy, whitish, membranous
deposits on them. These cats may continue to eat, but appear painfully thin. The dry form is not as obvious and
seems to develop in cats with a stronger immune system. It may cause nervous system problems, paralysis, seizures,
depression, fever, anemia, kidney or liver failure, etc. This form usually takes longer to progress than the wet form.
The only treatment for FIP is supportive, and is ultimately not successful. The
only options once a positive test is obtained are to 1) take your chances with other cats, 2) euthanize the positive
cat, or 3) test all of your other cats and vaccinate ones who test negatively, although this can get pretty expensive.
The best way of dealing with FIP is to prevent it. A vaccination is available
for negative testing cats. The vaccine requires 3 doses, 3-4 weeks apart, and is about 80% effective.