EN
The occurrence of parasites in slaughter animals between 1980—1991 in the Olsztyn province was analysed. Out of 2 231633 slaughter pigs trichinellosis was found in 20 animals (0.0009%), hydatidosis in 9037 (4.047%), cysticercosis in 80 (0.0036%) and liver fluke in 27 (0.0012%). In cattle (221 971 animals) cysticercosis was recorded in 8042 (3.62%), liver fluke in 62 662 (28.23%) and hydatidosis in 41 (0.018%). Of 15 369 examined sheep liver fluke was observed in 1460 animals (9.5%) and hydatidosis in 106 (0.69%). The post mortem examinations pointed to a significant extensiveness of parasitic invasions, particularly liver fluke in cattle and sheep (28.33% and 9.5% respectively), cysticercosis in cattle (3.62%) and hydatidosis in pigs (4.04%).