Pathological investigation on necrotic enteritis in desi chicken

The death cause in 15 desi chicken (aged 56–78 days), presented for postmortem examination in the Department of Veterinary Pathology, B.S. College of Vety. Medicine & Research Centre, Bikaner was investigated. After recording clinical history, birds were necropsied and specimen collected from intestinal lesions for isolation and identification of causal agent. Tissue samples were collected in 10% buffered formalin for histopathology. The birds had clinical history of severe depression, diarrhoea, reluctance to move, ruffled feathers and sudden death. Carcasses were severely dehydrated and emaciated. Mid intestines showed ballooning with foul smell, abnormally thick mucosa with yellowish brown diphtheritic membrane and varying degrees of haemorrhage. Histopathological study showed necrosis of enteroepithelial cells with marked desquamation, increased cellular infiltration in lamina propria and fibrin mixed with cellular debris adherent to intestinal mucosa. Gram positive, anaerobic bacilli were isolated which produced inner zone of hemolysis and outer zone of partial haemolysis when incubated at 37°C on blood agar medium. On biochemical character-ization, bacterial cultures were indole-and catalase-negative, fermented dextrose, lactose and sucrose with acid production but not mannitol. The deaths were established due to necrotic enteritis caused by clostriadial infection.