Feline infectious peritonitis.

Feline infectious peritonitis is a noncurable viral disease affecting cats worldwide. Recent evidence suggests that the FIPV has evolved as a deletion mutation of FECV. Immune complex deposition and vasculitis with pyogranulomatous lesions are the hallmark of FIP. The only definitive antemortem diagnostic test for FIP is histopathologic examination of tissue. Ocular manifestations occur commonly with noneffusive FIP. The most common clinical sign is a bilateral granulomatous anterior uveitis often accompanied by chorioretinitis. Treatment of ocular FIP is symptomatic, and the mainstay of palliative therapy is topical or systemic corticosteroids or both.