What is FIP? FIP (Feline Infectious Peritonitis) is a serious disease in cats caused by a mutation of the feline coronavirus. It affects the immune system and can lead to fever, weight loss, fluid buildup, and organ inflammation. Without treatment, it was once considered almost always fatal. Is there treatment? Yes. Antiviral medications like GS-441524 have been shown to successfully treat FIP. However, there is no FDA-approved FIP drug yet in the U.S. Why only a few pharmacies? Because the medi