Feline Infectious peritonitis intra vitam diagnosis: Approach and methods

Feline infectious peritonitis (FIP) is a severe multi-systemic fatal immune-mediated disease of cats associated with feline coronavirus (FCoV) infection. Two clinical forms of FIP were described: effusive or wet and non-effusive or dry. Although the suspicion of FIP in effusive form is easier than in non-effusive, the confirmatory diagnosis is challenging. We reviewed the present approach and methods used in diagnostic of FIP. Ante-mortem diagnosis of FIP requires integrated analysis of epidemiological, clinical and laboratory data. Epidemiological data relevant for FIP suspicion are: the age of cat (4–36 months of age) and origin (multi-cat households). Signs relevant for FIP suspicion are: moderate pyrexia, abdominal distension, weight loss, anorexia, dyspnea, pericardial effusions, jaundice, ocular lesions and neurological signs. Imagistic exams mayreveal: effusions, masses on the kidneys and mesenteric lymph nodes, abdominal lymphadenopathy, irregular splenic and renal surfaces. Peritoneal exudatemaybe clear to moderately cloudy, viscous and elevated protein with Rivalta-test positive. Cerebrospinal fluid analysis revealed leukocytosis and elevated protein. Urine analysis is characterized by hyperbilirubinuria. FCoV diagnosis is mandatory and consist in antibody titration, antigen detection or PCR-based tests, but the tests can’t differentiate pathogenic and non-pathogenic strains. Actually, Rivalta-test, histopathology and IHC with detection of virus bodies into macrophages are the reliable confirmatory procedure in clinical practice.