Feline infectious peritonitis, once universally fatal, can now be treated effectively with antiviral medications in many cats, representing a revolution in welfare outcomes for affected individuals.
Before effective antiviral treatment became available, FIP was a death sentence causing progressive suffering as effusion or granulomatous disease advanced. The development of effective antivirals has transformed FIP from a uniformly fatal condition to a manageable disease in most cases. Cats responding to treatment typically show dramatic improvement within the first week. Welfare is now primarily determined by timely diagnosis, access to effective medication, and owner compliance with the lengthy treatment course. Cost of treatment remains a barrier for some owners, raising equity concerns about access to what is now an effective therapy.