Photosensitivity in South Africa. IV. Pathological changes in the liver in ovine photosensitivity caused by the plant Asaemia axillaris (Thunb.) Harv. Ex Jackson.

Hepatic lesions in 4 field cases of ovine hepatogenous photosensitization caused by the plant, Asaemia axillaris (Thunb.) Harv. Ex Jackson, are described. The liver was usually swollen, friable and yellowish-brown, with distinct lobulation. Microscopically, the lesions ranged from peripheral coagulative necrosis in 1 animal to others with scattered single cell or small foci of necrosis as well as hepatocellular degeneration and unrest, ductular proliferation, portal fibroplasia and cholestasis. The liver lesions are compared with those of previously reported experimental cases of A. axillaris poisoning in sheep. The significance of zonal necrosis and factors that may have a bearing on their production in different hepatotoxic plant poisoning in sheep and cattle in South Africa are discussed.