Feline Infectious Peritonitis (FIP)

“In memory of Kevin Skavnak (a cat) whose spirit, and sweet demeanor will always be remembered.
We should all live life as Kevin did, with zest and wonder.”

Feline infectious periotonitis (FIP) is a disease that is caused by the feline enteric coronavirus. This virus is very prevalent and 80 – 90% of cats are seropositive for the virus. The disease FIP results when a mutation of the virus occurs in an individual cat. FIP causes widespread infiltration of the body’s organs with pyogranulomatous inflammatory tissue. This leads to failure of the affected organs and death.

The virus is shed in the feces of infected cats. Cats coming in contact with the infected stool can then become infected with the virus. Multicat households, rescue or shelter animals have a greater risk of infection than households with fewer than 5 cats. While the coronavirus is contagious, FIP is not. This is because a mutation must occur after infection to cause the disease.

Clinical signs vary. Most cats with the enteric virus show no clinical signs or signs of gastrointestinal distress (i.e diarrhea). Cats that develop FIP are generally less than one year of age and clinical signs vary depending on what body system is infected.

There are 2 forms of FIP. The effusive (wet) form is acute and develops 4-6 weeks after a stressful event (i.e. going to a new home, surgery or arrival at a shelter). This form is rapidly progressive and clinical signs are related to leakage of protein and fluid into body cavities. Clinical signs include lethargy, inappetence, weight loss, fluctuating fever and ascites (fluid buildup in the abdominal cavity). If fluid builds up in the chest cavity, respiratory difficulty/distress may be noted. The Non effusive (dry) form can take weeks to months to develop, and clinical signs are vague. Mild temperature fluctuations, decreased appetite, weight loss may be present. Ocular (eye) changes may occur as well as gastrointestinal signs (vomiting, diarrhea) and neurologic abnormalities. The signs depend on what organ system is affected.

There are no definitive diagnostic tests available. This is due to the fact that the virus can mutate in a variety of ways and it is often different from one cat to the next. Diagnosis is generally made on the basis of history, clinical signs, elevated blood protein levels (particularly globulins) and evaluation of body fluids if present.

There is currently no specific treatment for FIP. Some antiviral drugs have shown promise in experimental studies but they are not commercially available, are in short supply and are very expensive. Treatment is basically supportive, control clinical signs and relieve pain without curing the disease as well as treating any concurrent illnesses.

Despite the widespread presence of the feline coronavirus, it is important to remember that only 5- 10% of cats infected with the feline coronavirus develop FIP.