Cat Feline Infectious Peritonitis Long-Term Antiviral Care

Recent antiviral breakthroughs have transformed FIP from a near-universally fatal disease to one that is treatable in most cats.

Key Facts

FIP is caused by a mutated form of feline coronavirus that causes systemic, often fatal inflammation
FIP was historically fatal in nearly 100% of cases; effective treatment was unavailable until 2019
GS-441524 and remdesivir-based antivirals have cure rates exceeding 85-90% in clinical studies
Treatment requires 12 weeks of daily antiviral injections or oral medication
Wet FIP (with effusion) and dry (granulomatous) FIP respond differently and require individualized protocols
Relapse occurs in approximately 5-10% of cases and often responds to extended or combination treatment
Access to these medications has been limited by regulatory status in some countries, though availability is improving

Welfare Considerations

Before antivirals, FIP diagnosis was a death sentence, causing immense suffering in young cats who deteriorated rapidly. Long-term antiviral treatment requires daily handling and injections, which is stressful for cats and demanding for owners. Monitoring protocols during treatment allow early detection of relapse or treatment resistance.

What You Can Do

Seek a vet experienced with FIP antiviral protocols if your cat is diagnosed
Join FIP support groups that provide guidance on sourcing and administering treatment
Monitor weight, appetite, and activity weekly during treatment and report changes promptly
Complete the full 12-week treatment course even if the cat appears fully recovered
Advocate for regulatory pathways that make FIP antivirals more accessible and affordable