Feline Infectious Peritonitis (FIP)
by Margaret Schill
Feline infectious peritonitis (FIP) is a serious, nearly always fatal viral disease caused by a coronavirus. A common, relatively benign form of feline intestinal coronavirus called FECV (feline enteric coronavirus) sometimes mutates into a disease-causing form, called FIPV (feline infectious peritonitis virus). If a cat’s immune system responds poorly, the mutant FECV may cause the systemic infection called FIP. The organs of the cat's body get infiltrated with inflammatory tissue, called “pyogranulomas.” The inflammation then leads to failure of the organs that were infiltrated. Symptoms will vary depending upon which organs were affected. In brief, what happens is that the cat's immune system over reacted to the virus.
Recent research has shown that mutant FECVs arise within an individual cat, possibly due to a hereditary predispostion. While cats don't "catch" FIP from other cats, they can acquire the FECV virus from the other cat or the environment shared with the infected cat. Then, some cats' bodies will mutate the harmless FECV virus into FIP, as happened to the first infected cat. The benign FECV is spread primarily by the fecal-oral route and, to a lesser degree, through saliva or respiratory droplets. The virus can remain in the environment and in dried feces on cat litter for 3 to 7 weeks, so scrupulous cleaning of litter boxes is important to reduce the amount of virus in the environment. Litter boxes should scooped at least daily and dumped and disinfected at least weekly. Tracked litter should be vacuumed or swept up promptly. Litter boxes should be kept away from food and water bowls.
There are two forms of FIP, the dry form and the wet form. The “wet” form of FIP, includes the accumulation of thick, yellow fluid in the chest or belly, causing distention of the belly. In the “dry” form, the cat often has vague clinical signs, such as a fever, lethary, not eating, losing weight, and a dull coat. Many cats with dry FIP become jaundiced. The inner eyelids may look yellow. If the cat has a pale nose, you may notice that that looks yellow. Many cats with dry FIP get signs in their eyes. Usually the iris (the coloured part of the eye around the pupil) changes color; parts of it may appear brown. Both forms are felt to have 100% mortality.
None of the current tests for FIP accurately differentiate the FIP mutant from the normal enteric coronavirus. The only certain diagnoses are made at the time of a necropsy exam (autopsy).
When testing is done and all other causes of the symptoms are ruled out, one might conclude that the cat likely has FIP. If tests indicate FIP and your cat has the fluid characteristic of the wet version, the diagnosis can be straightforward.
Once the FIP virus gains access to the cat's body it takes about 2 weeks for the virus to become widespread. After that, the length of time for clinical symptoms to appear varies, but rarely exceeds 2 months. Most cats with FIP will die within 2 to 11 months from the damage caused by the virus and secondary problems such as kidney or liver failure. There is no treatment that has been proven to work on a consistent basis for FIP. Aggressive treatment of the secondary problems and suppression of the immune system with corticosteroids or other medications may prolong the lifespan of infected cats.
There is a vaccine sold for FIP, but it is controversial. It has been found to be safe and approximately 50-75% effective. The vaccine is a modified-live temperature-sensitive viral mutant administered nasally.
The FIP virus itself lasts in the environment for up to 6 or 7 weeks. It is easily killed with disinfectants, so careful cleaning of a home may help prevent the spread of the disease in a household with more than one cat. If an only cat died from FIP, one should wait 6 or 7 weeks before bringing a new cat into the home.
More information
More information :
http://animalhealthchannel.com/fip/
http://www.peteducation.com/article.cfm?cls=1&cat=1316&articleid=212
http://www.vetinfo.com/cfip.html#Feline%20Infectious%20Peritonitis%20(FIP)
http://www.maxshouse.com/feline_infectious_peritonitis.htm
http://www.winnfelinehealth.org/health/FIP.html
