The histopathology of Wesselsbron disease in sheep

Abstract

1. The histopathology of Wesselsbron disease is described. The lesions are mainly confined to the liver. This organ shows fatty infiltration, bile pigmentation, necrobiosis of the liver cells and infiltration of lymphocytes and neutrophils. The histological picture tends to be variable and the lesions in experimentally infected cases are of a much milder degree compared to those observed in natural cases. 2. Immunisation of pregnant ewes produces meningo-encephalitis in the foetuses. 3. The differential diagnosis is discussed and it is suggested that enzootic icterus probably played a role during the 1957 outbreak of Wesselsbron disease.