Studies on an idiopathic syndrome in the brown hare (Lepus europaeus P.) and mountain hare (Lepus timidus L.) in Sweden, with special reference to hepatic lesions.

At routine post mortem examinations performed at the National Veterinary Institute (NVI), Uppsala, Sweden, during November 1983-May 1984, a syndrome principally characterized by an acute hepatosis was found in 85 out of 177 brown hares (Lepus europaeus P.). The hepatic lesions consisted of periportal or extensive necrosis and haemorrhages. Concomitant changes in other organs were tubular necrosis in the kidneys, acute catarrhal enteritis, severe congestion, oedema and haemorrhages of the lungs, hyperemia of the spleen, and in some cases jaundice. A supplementary retrospective study of liver sections from another 388 brown hares and 202 mountain hares (Lepus timidus L.), autopsied at NVI during 1980-1985, revealed 35 additional cases of the acute hepatosis, 32 being in brown hares and 3 in mountain hares. The histopathology of the liver lesions may suggest a toxic etiology.