Changes in the frontal sinuses of the weasel (Mustela nivalis) in Poland possibly caused by nematodes or trematodes.

The presence of parasitic Nematodes was determined by visual assessment of damage to the 271 weasel skulls (154 males and 117 females). The damages were attributed to Skrjabingylus nasicola (Leuckart, 1842) or Troglotrema acutum (Leuckart, 1842) (on the basis of it's appearance and relevant papers). The frequency of infestation by both parasites was 38%. It was higher in females and also increased along with age. A significant dependence between skull length of adult specimens and infestation rate was found.