Feline infectious peritonitis (FIP) was once nearly always fatal. Today, antiviral medications are achieving remission in many cats. Early diagnosis is the key to successful treatment.
A temperature above 39.5°C (103°F) lasting days or weeks, unresponsive to antibiotics — a hallmark early sign of FIP.
Sudden disinterest in play, reduced eating, spending all day sleeping. Especially alarming in young cats.
Fluid accumulation in the abdomen (ascites) or chest (pleural effusion). Chest fluid causes breathing difficulty.
Uveitis, changes in iris color. More commonly seen in dry-type FIP.
Stumbling, seizures, or hind limb weakness. Indicates dry-type FIP affecting the central nervous system.
Yellow tint to the skin, eyes, or gums — a sign that the liver is being affected.
FIP is caused by a mutated form of feline coronavirus (FCoV). Many cats carry FCoV asymptomatically, but in 5–10% of infected cats the virus mutates into the disease-causing form. Why some cats develop FIP and others don't is still not fully understood.
FIP comes in two main forms: wet (effusive) type, which produces fluid buildup in the abdomen or chest, and dry (non-effusive) type, which forms granulomas in organs. Mixed forms exist too. Kittens and cats in multi-cat environments are at higher risk.
Antiviral drugs — including GS-441524 and molnupiravir — have changed the outlook for FIP dramatically. Remission rates in treated cats have been reported as high as 80–90% in some studies. Veterinary-approved formulations are becoming more accessible. Early diagnosis significantly improves outcomes.
CatsMe helps you track changes in your young cat's weight, appetite, and activity level — the early warning signs that something may be wrong. The sooner FIP is diagnosed, the better the odds of a successful treatment outcome.
Get Started FreeFIP itself does not spread directly between cats. However, the underlying feline coronavirus (FCoV) does spread through fecal contact. Since most cats with FCoV never develop FIP, the risk to other cats in a household is moderate but not negligible.
Antiviral treatment over 84 days can range from $3,000 to $10,000+ depending on the drug and your cat's weight. Costs have dropped as veterinary-approved drugs have become available. Check whether pet insurance covers it before starting treatment.
There is no fully reliable prevention. Minimizing stress, maintaining good litter hygiene, and managing the number of cats in a household can reduce the risk of FCoV spreading and mutating. Most FCoV-positive cats never develop FIP.