Feline Infectious Peritonitis: Welfare and Treatment Advances in 2026

FIP, formerly invariably fatal, can now be treated with antiviral drugs in most cases, representing one of the most significant recent advances in feline welfare.

Key Facts

FIP is caused by a mutation of feline enteric coronavirus that occurs in individual cats after infection
Before antiviral treatment development, FIP was almost invariably fatal with a median survival of days to weeks
GS-441524 antiviral therapy achieves sustained remission in approximately 85-90% of treated cats
Treatment requires 84 days of daily injection or oral medication with monitoring for relapse

Welfare Considerations

FIP historically caused rapid, fatal welfare compromise through fluid accumulation, organ failure, and neurological disease. The development of GS-441524 antiviral therapy has transformed FIP from invariably fatal to treatable in most cases — one of the most dramatic welfare advances in feline medicine in decades. Treatment requires intensive commitment from owners but most cats achieve sustained remission and return to normal quality of life. Access to medication has historically been limited by regulatory status in some countries, though this is improving. Early diagnosis enables treatment before severe welfare compromise occurs. Monitoring for relapse after treatment completion is essential.

What You Can Do

Seek specialist veterinary assessment immediately if FIP is suspected based on clinical signs and diagnostic tests
Ask your vet about GS-441524 or licensed antiviral therapy and access routes in your country
Commit to the full 84-day treatment course with appropriate monitoring for optimal welfare outcome
Monitor for relapse signs for 12 months after treatment completion and report any concerning signs promptly