Feline Infectious Peritonitis or FIP

Many cats, if not most, are exposed to feline coronavirus (FCoV) when they are young.  It causes a mild diarrhea that usually clears without treatment.  The virus is spread from cat to cat via saliva, nasal discharge and stool.  The virus is stable in the environment for a few days to a few weeks but is easily killed by most cleaning agents.  The majority of cats who have had FCoV go on to live normal lives.

photo by Lucie B Photography

The problem is that, in some kittens and cats, the virus will mutate into the deadly Feline Infectious Peritonitis (FIP).  FIP comes in two forms: the wet (or effusive) form and the dry (or non-effusive) form.  The wet form is the most common and it tends to affect cats under 2 years of age.  This form of FIP results in fluid leaking into the chest and/or abdomen.  The dry form more commonly affects adult cats and causes build-ups of inflammatory lesions in various organs.  The signs of this form of the disease depend on the organ involved.  

There is no way to prevent cats from developing FIP.  Although rare, any individual cat can mutate FCoV into FIP.  Research has shown that there is a genetic component to developing FIP, so some related cats and some breeds are more likely to mutate the coronavirus into FIP.  The mutated FIP virus itself is not contagious. 

A new test available through veterinarians can distinguish between cats with FCoV and cats with FIP.  Unfortunately, this test can only be run after the cat has signs that go along with FIP;  it is usually run on chest or abdominal fluid.  There is no test that can tell if a healthy cat will develop FIP later in life.

The worst part of all this is that once a cat has developed FIP, there is nothing that will cure the disease.  Some cats, mainly those with the dry form, feel better for a short time with treatment but in the end it is always fatal.

References:

Small Animal Internal Medicine 2nd edition, Nelson and Cuoto.

International Cat Care website: http://icatcare.org/advice/cat-health/feline-infectious-peritonitis-fip

article written by:

Stephanie Altneu, DVM

Companion Animal Hospital Vernon Hills