Companion Cat Feline Infectious Peritonitis: Welfare in a Previously Fatal Disease

Feline infectious peritonitis (FIP) was once almost universally fatal, but antiviral treatments now offer a high chance of cure, transforming the welfare outlook for affected cats.

Key Facts

FIP is caused by a mutation of feline coronavirus that leads to systemic inflammatory disease
The disease occurs in two forms: wet (effusive) FIP with fluid accumulation, and dry (non-effusive) FIP with granulomatous lesions
Without treatment, FIP was almost always fatal within days to weeks of diagnosis
Nucleoside analogue antivirals (GS-441524 and related compounds) have demonstrated remission rates of 80-90% in clinical trials
Treatment requires daily injection or oral administration for a minimum of 84 days
Cost is a significant barrier to access in many countries; unlicensed versions of the drug are available online at lower cost
The drug was formally licensed in the EU and other regions from 2023 onwards
Young cats under two years are most commonly affected; FIP was previously a leading cause of death in young cats

Welfare Considerations

The development of effective antiviral treatment for FIP is one of the most significant welfare advances in small animal medicine in recent years. A disease that was previously a death sentence now has an 80-90% cure rate with appropriate treatment. The primary remaining welfare challenge is access: treatment costs are high, and many cat owners cannot afford the full course of treatment. Advocacy for affordable access to life-saving medications, along with owner and vet awareness that FIP is now treatable rather than invariably fatal, are the most important current welfare priorities for this disease.

What You Can Do

If your cat is diagnosed with FIP, seek a vet experienced in antiviral treatment immediately
Join online support groups such as the FIP Warriors community for guidance on access and treatment
Advocate for affordable access to licensed FIP antivirals through your vet and animal welfare organisations
Support cat welfare organisations that provide financial assistance for treatment costs
Donate to FIP research programmes working on improving treatment access and efficacy