Infectious necrotic hepatitis caused by Clostridium novyi type B in a goat with listeriosis.

A 6-y-old postpartum Nubian crossbreed goat was submitted for postmortem examination following a clinical course of ataxia, lateral head tilt, and recumbency. The liver had a poorly defined, pale-yellow focally extensive lesion and focal thickening of bile ducts. Histologically, an area of extensive coagulative necrosis was surrounded by many viable and degranulated neutrophils and gram-positive bacilli, which were identified as Clostridium novyi by immunohistochemistry. Numerous neutrophilic infiltrates were observed in the brainstem. PCR on DNA extracted from hepatic tissue was positive for the fliC, tcna, and tcnb genes of C. novyi type B. Additionally, PCR testing of brainstem tissue was positive for the hlyA gene of Listeria monocytogenes. To our knowledge, infectious necrotic hepatitis (INH), confirmed by molecular testing and with concurrent listeriosis, has not been reported previously in a goat. Clostridial hepatitis in animals is typically triggered by anaerobic conditions within the liver parenchyma, which facilitate the germination of dormant spores and the subsequent release of potent toxins. Although flukes were not observed, the presumptive inciting hypoxic event leading to parenchymal necrosis in this case was Fasciola hepatica larval migration. Because the clinical and pathology features of INH caused by C. novyi type B and bacillary hemoglobinuria caused by C. haemolyticum are nearly identical, molecular differentiation is essential to establish an accurate etiologic diagnosis.