US veterinarians can now treat feline infectious peritonitis (FIP) with GS-441524, an antiviral tablet, available through Stokes Pharmacy. Clinical studies show over 80% survival rate with GS-441524, with a 96% survival rate if cats survive the first 48 hours of treatment. The drug is recommended for various FIP types, including effusive, non-effusive, neurological, and ocular. Treatment typically lasts 84 days, with dosages adjusted based on weight and clinical response. The availability of regulated GS-441524 addresses issues with unregulated black market drugs, providing ethical treatment options for cats with FIP.