Definition of Feline Infectious Peritonitis
Feline infectious peritonitis (FIP) is a progressive, systemic and frequently fatal disease of domestic and exotic cats caused by coronaviral infection.
How Feline Infectious Peritonitis Affects Cats
FIP is characterized by an insidious onset of persistent fever that is unresponsive to antibiotic treatment, inappetance, gradual weight loss and possibly abdominal enlargement. It is most common in young cats, up to 3 years of age, of either gender and of any breed (although males and purebred Asian breeds, such as the Birman and Himalayan, may be predisposed). It causes stunted growth in young kittens. Affected cats also may be depressed and have a dull, rough hair coat, eye inflammation and possible neurological signs as well.
There are two clinical presentations of FIP, called the wet (effusive) form and the dry (non-effusive) form. They cause different clinical signs in affected cats, but the treatment options and prognosis are unfortunately equally poor. The wet form of FIP causes an accumulation of fluid in the chest and/or abdomen, leading to respiratory difficulty and/or a pot-bellied appearance. The dry form affects the same parts of the body but does not cause fluid accumulation. The dry form may eventually progress to the wet form if the patient lives long enough.
Cats with FIP are infectious to other cats during the initial two to four week period immediately following infection, when large amounts of virus are shed. After this stage, the virus becomes inactive and affected cats will not show clinical signs of disease.
Causes of Feline Infectious Peritonitis
Feline infectious peritonitis is caused by several genomic types of coronavirus. Currently, there is no way to distinguish between the forms that cause asymptomatic infections and those that are fatal.
Preventing Feline Infectious Peritonitis
The main mode of transmission appears to be from asymptomatic carrier queens to their kittens and from fecal-oral or saliva contact. Early weaning may help break the cycle of transmission. Routine hygiene to disinfect cages, water and food bowls and the environment, is very helpful to inactivate viral reproduction. Keeping cats indoors also can help prevent infection with this virus. There is a modified live intranasal vaccine available against the FIP virus. Unfortunately, it is not extremely effective and is not currently recommended for routine use in low-risk cats.
Special Notes
FIP is difficult to diagnose, control and prevent. When it infects catteries, the consequences can be catastrophic. Diagnosing FIP can be both difficult and frustrating since there are no specific tests that are completely reliable. Diagnosis is often based on a combination of blood tests, fluid analysis, radiographs (x-rays) and tissue biopsies. Cats with the wet form of FIP generally die within 2 months of the onset of clinical signs; cats with the dry form have a more chronic course of disease, but it also is generally fatal. There is no effective treatment for FIP, and euthanasia is usually recommended. Recovery is extremely rare.
Even though a vaccine against FIP is available, most veterinarians do not recommend routine vaccination against FIP. Vaccination is, however, recommended for cats that commonly go outdoors and come in contact with other free-roaming cats. Vaccination is also recommended for cats that come from households that have had a cat with FIP.