EN
In the years 1985-1988 in the Białowieża Forest and in the woods in the vicinity of Olsztyn, 130 deer, 136 roe-deer, 52 bisons and 40 cattle were subject to parasitological section. Seven species of tissue nematods of the superfamily Filarioidea were detected. Onchocerca jakutensis, O. garmsi and Cutifilaria wenki in deer, Dipetalonema rugosicauda in roe-deer, and Onchocerca lienalis and O. gutturosa in bison and cattle are first records of these species in Poland. The bison is a new host for O. lienalis and O. gutturosa, the roe-deer - for O. flexuosa.