Cat Feline Infectious Peritonitis: Hope After a Once-Fatal Diagnosis

Feline infectious peritonitis (FIP) was once universally fatal. New antiviral treatments have transformed the prognosis, though access and cost remain welfare challenges.

Key Facts

FIP is caused by a mutated form of feline coronavirus (FCoV) that becomes virulent in some cats
It causes either effusive (wet) disease with fluid accumulation or non-effusive (dry) disease with granulomas
FIP was previously fatal in nearly 100% of cases — median survival was weeks after diagnosis
Antiviral drugs (GS-441524, molnupiravir) have shown remission rates of 80-90% in clinical studies
Treatment requires 12 weeks of daily medication and is currently very expensive in many countries
Cost of treatment can exceed thousands of dollars, creating equity and welfare access issues

Welfare Considerations

FIP causes significant suffering: fluid accumulation, organ failure, neurological signs, and progressive deterioration. Previously, diagnosis was a death sentence — now it can be a treatable condition. The welfare transformation that antiviral treatments represent is profound, but access barriers mean many cats still die from FIP unnecessarily. High drug costs, limited veterinary availability of licensed products, and use of unlicensed generic medications create inconsistent welfare outcomes depending on owner finances and geography. Advocacy for affordable, accessible FIP treatment is a welfare priority with immediate, significant impact.

What You Can Do

If your cat is diagnosed with FIP, ask your vet about antiviral treatment options urgently
Connect with FIP support groups who can advise on accessing treatments including generic alternatives
Advocate for pharmaceutical companies to make licensed FIP treatments more affordable globally
Support organisations working to improve veterinary access to FIP antivirals in LMICs
Raise awareness that FIP is now treatable — early diagnosis and treatment gives the best chance of remission