Feline infectious peritonitis (FIP) was once a near-universal death sentence for cats, but new antiviral treatments have transformed outcomes for many affected animals.
FIP represents one of the most acute suffering experiences in companion cat medicine: affected cats develop fluid accumulation in body cavities, neurological symptoms, eye inflammation, and progressive deterioration over weeks. Before effective antivirals, the only welfare-consistent option was often early euthanasia. The emergence of GS-441524 transformed FIP from a death sentence to a treatable disease — but access inequities have created a welfare divide. Cats in wealthier households or countries with licensed drug access can now survive FIP at high rates. Cats in lower-income contexts often still die from a now-preventable disease. Veterinary licensing delays and high treatment costs represent welfare failures that policy could address.