What is FIP?
FIP is a viral disease of cats that can affect many systems of the body. It is a progressive disease and almost always fatal. It is found worldwide and affects not only domestic cats, but many wild ones as well, including cougars, bobcats, lynx, lions, and cheetahs.
Which cats are more likely to develop FIP?
As you would imagine, the cats most likely to develop FIP are those with the weakest immune systems. This includes kittens, cats infected with feline leukemia virus (FeLV), and geriatric cats.
The largest number of FIP cases occurs in young cats. Kittens are often infected when they are 4 to 6 weeks old, when the antibody protection they received from their mothers through the milk is declining. Kittens usually start showing signs of FIP when they are between 3 months and 2 years of age. Most of the kittens with FIP die between 8 and 18 months of age.
When infections with feline leukemia virus (FeLV) were more common, infections with FeLV and FIPV were often seen together because FeLV suppressed the immune system. Now that FeLV is less common only 5% of cats with FIP are also infected with FeLV.
We rarely see FIP in cats between 3 and 10 years of age. However, starting at 10-12 years of age, the immune systems of these older cats apparently decline, making them more susceptible.
FIP has been shown to be more common in certain breeds and lines. It appears to be more common in Persians, for example. It is unclear whether these breeds are more susceptible because of their genetics or whether they are exposed to FCoV more often since many of them live or come from catteries.
We’ve not encountered FiP personally, but in the last 6 months, have come to know of 3, all involving kittens 6 months or younger. So if you have kittens, please be careful. And if you have more than one, isolate and get them tested before allowing interaction. This may make all the difference in the mortality rate for your kittens.
(Created: 24 May 06)