Cholangiohepatitis in broiler chickens in Japan: histopathological, immunohistochemical and microbiological studies of spontaneous disease.

Forty-five broiler carcasses from 6 different flocks were condemned due to liver lesions at processing meat inspection, and collected for pathological and bacterial examinations. All affected chickens showed liver enlargement with discolouration and an apparent acinar pattern. The enlarged gallbladder and the extrahepatic bile ducts contained yellow inspissated cream-coloured material. Histopathologically, extensive proliferation of bile ductules with fibrosis was observed in interlobular connective tissue, and it spread to form bridges with adjoining triads. Destruction and obstruction of portal bile ducts with multiple granulomas due to bacterial infection and outflow of the bile were frequently observed. Many Gram-positive bacilli were seen in the lesions, and they were identified as Clostridium perfringens by indirect immunofluorescence staining technique. Clostridium perfringens was isolated from affected livers. These findings are consistent with cholangiohepatitis. Therefore, it is suggested that C. perfringens might be important in the pathogenesis of cholangiohepatitis in broiler chickens.