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 3 years, and with the help of funds provided by the Winn Feline Foundation, our research group at University California Davis has conclusively demonstrated that naturally acquired FIP is a curable disease using a nucleoside analog called GS-441524 (Gilead). However, this drug is not yet available for use in cats. In its place, Gilead has provided 48 related nucleoside analogs and if any are found to be equivalent, they have agreed to provide the necessary animal rights. Preliminary data indicates that 3 or more of these drugs will have potent anti-FIPV properties and be non-cytotoxic in feline cells. The most promising of these compounds will be synthesized in much larger amounts and ultimately tested in cats for safety and efficacy. Another collaborator, Mark Olsen (Midwestern University) is creating a set of drug compounds targeting a different viral protein. 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.