Companion Cat Feline Infectious Peritonitis and Welfare

Feline infectious peritonitis (FIP) was until recently a fatal diagnosis in cats, but new antiviral treatments are revolutionizing outcomes and transforming the welfare picture for affected cats.

Key Facts

FIP is caused by a mutated form of feline coronavirus and was previously almost universally fatal once clinical signs appeared
It affects young cats most commonly, with 70-80% of cases occurring in cats under 2 years
Two forms exist: wet FIP with fluid accumulation and dry FIP with granulomatous lesions — both cause progressive debilitation
Antiviral drugs including GS-441524 and remdesivir have shown over 85% remission rates in clinical trials when used for 84 days
Treatment costs remain high — often several thousand dollars per cat — creating welfare inequity based on financial access
Regulatory approval of antivirals for feline FIP is now established in multiple countries after years of access through grey markets
Early diagnosis and prompt treatment significantly improve outcomes, making veterinary recognition and testing critical

Welfare Considerations

FIP was one of the most distressing diagnoses in companion cat medicine for decades — a young cat progressing rapidly to death with no treatment option. The emergence of effective antiviral treatment represents a genuine welfare revolution. Cats that previously would have died within weeks now achieve remission and return to normal life in the majority of treated cases. The remaining welfare challenge is financial access — treatment costs that exclude many cat owners. Advocacy for affordable access and continued regulatory approval are important welfare priorities to ensure that effective treatment reaches all cats who need it.

What You Can Do

Seek prompt veterinary assessment if your young cat develops fever, lethargy, fluid accumulation, or neurological signs
Discuss FIP antiviral treatment options with your veterinarian if FIP is suspected or diagnosed
Ask your vet about financial assistance programs or payment plans to access FIP antiviral treatment
Support advocacy organizations working to improve access to FIP antivirals and reduce treatment costs
Donate to research continuing to improve FIP treatment protocols and reduce treatment duration requirements