Cat Feline Infectious Peritonitis and Welfare

FIP (feline infectious peritonitis) was historically fatal in cats, but new antiviral treatments offer a welfare revolution for cats diagnosed with this previously terminal disease.

Key Facts

FIP is caused by a mutated form of feline coronavirus that causes fatal systemic inflammation in susceptible cats, typically under 2 years old.
Until 2021, FIP was virtually 100% fatal with palliative care the only option after diagnosis.
GS-441524, an antiviral nucleoside analogue, achieves remission in approximately 80-90% of treated FIP cats.
Treatment requires 12 weeks of daily injections or oral medication with ongoing monitoring for relapse.
Regulatory approval of licensed GS-441524 formulations has expanded access to this life-saving treatment.

Welfare Considerations

FIP represents one of the most dramatic welfare transformations in companion animal medicine in recent decades. A disease that meant certain death for thousands of young cats annually is now largely treatable. However, treatment is expensive and access is unequal — many cat owners cannot afford the 12-week course. Welfare organisations advocate for reduced costs, broader insurance coverage, and continued research into this devastating disease to make treatment accessible to all affected cats.

What You Can Do

Ask your vet about GS-441524 treatment if your cat is diagnosed with FIP — survival is now possible.
Support FIP advocacy organisations working to expand access to affordable antiviral treatment.
Ensure pet insurance covers FIP treatment when selecting a policy for your cat.
Donate to feline medicine research charities working on FIP prevention and treatment optimisation.