What Is FIP? Complete Guide to Types, Early Warning Signs & High-Risk Cats

Feline Infectious Peritonitis (FIP) was once labeled an incurable death sentence for cats. Triggered by mutated feline coronavirus (FCoV), this systemic inflammatory disease mainly attacks kittens and young cats under 2 years old. Most cats carry mild intestinal coronavirus without illness; only rare viral mutation combined with weak immunity leads to FIP.

FIP splits into three core clinical types: wet (effusive), dry (non-effusive), and complicated neurological/ocular FIP.

Fluid builds up in abdomen or chest. Visible swollen belly, labored breathing, persistent fever unresponsive to antibiotics, rapid weight loss, poor appetite. Progresses fast within 1–3 weeks.

No obvious effusion. Granulomas damage organs, eyes or brain. Classic signs include cloudy uveitis, unsteady gait, head tilt, recurring fever and hidden organ lesions, easily misdiagnosed.

Severe subtype of dry FIP, with seizures, paralysis, pupil deformation, vision loss. Higher treatment dosage is required.