EN
Pathomorphological studies were carried out on 119 European bisons of both sexes and various ages shot in the years 1990-1994 in the Białowieża forest during breeding selection. The culled animals were old and ill, but some healthy ones were also eliminated to keep the herd size under control. The bisons were examined at necropsy and histopathologically. Pathomorphological lesions caused by parasites were observed most frequently in the lungs and livers. Myocardial parasitic lesions were also quite common. In a large number of male bisons some lesions were found in the prepuce and penis.