What is FIP?
Feline Infectious Peritonitis
Feline infectious peritonitis (FIP) is a viral disease of cats caused by certain strains of a virus called the feline coronavirus. Most strains of feline coronavirus are found in the gastrointestinal tract and do not cause significant disease. These are referred to as feline enteric coronavirus (FeCV). Cats infected with FeCV usually do not show any symptoms during the initial viral infection, but may occasionally experience brief bouts of diarrhea and/or mild upper respiratory signs from which they recover spontaneously. FeCV-infected cats usually mount an immune response through which antibodies against the virus are produced within 7-10 days of infection. In approximately 10 percent of cats infected with FeCV, one or more mutations of the virus can alter its biological behavior, resulting in white blood cells becoming infected with virus and spreading it throughout the cat’s body. When this occurs, the virus is referred to as the FIPV. An intense inflammatory reaction to FIPV occurs around vessels in the tissues where these infected cells locate, often in the abdomen, kidney, or brain. It is this interaction between the body’s own immune system and the virus that is responsible for the development of FIP. Once a cat develops clinical FIP, the disease is usually progressive and almost always fatal without therapy that has recently become available, but that has yet to be approved to treat FIP in cats by the Food and Drug Administration (FDA) (see below). To our knowledge, coronaviruses cannot be passed from infected cats to humans.