Feline infectious peritonitis (FIP), caused by mutant feline coronavirus known as FIPV, is a common and generally lethal disease of domestic cats. Over the past 5 years, and with the invaluable assistance of funds provided by the Winn Feline Foundation Bria Fund, our research group at University California Davis has conclusively demonstrated that naturally acquired FIP is a curable disease. Through a variety of collaborations, we have obtained and tested a set of 106 antiviral agents and have determined that 25 of these compounds inhibit FIPV replication. Based on results of human studies, we believe that a combined anticoronaviral therapy (CACT) approach, simultaneously targeting multiple steps of the FIPV life cycle, will be most effective in treating cats with all forms of FIP disease, including inflammation of the brain and eye. The results of our initial studies, although not immediately yielding a marketable drug for cats, lead us to conclude that that FIP is in fact a curable disease.