An attempt to deworm European bison (Bison bonasus) in the European Bison Breeding Center of Białowieża National Park with Alphalben (albendazole).

Parasitic infections are one of the most important factors affecting the health and condition of wild ruminants, including bison, particularly those kept in closed breeding, and regular deworming is important. The aim of this study was to investigate the effectiveness of deworming European bison in BNP (Białowieża National Park) reserves with Alphalben (albendazole). The drug was administered orally at a dose of 15 mg/kg body weight. To assess the effectiveness of the treatment, samples of bison faeces were examined by flotation, sedimentation and Baermann methods before deworming and 14 days after drug administration. Treatment efficacy was calculated according to the Faecal Egg Reduction Test (FERCT). Deworming was not effective against gastrointestinal nematodes of the Trichostrongylidae family, Fasciola hepatica or Paramphistomum cervi flukes, or Eimeria bovis coccidia. A deworming efficacy of 100% was recorded against the lung nematodes Dictyocaulus viviparus, the nematodes Nematodirus sp. and Aonchotheca sp., the tapeworms Moniezia sp. and the coccidia Eimeria zuernii, E. cylindrica, E. brasiliensis and E. subspherica. The ineffectiveness of deworming against the most dangerous bison parasites (gastrointestinal nematodes and flukes) may indicate the development of albendazole-resistant parasite strains, possibly due to long-term, repeated administration.