title: The annual cycle of shedding Eimeria oocysts by European bison (Bison bonasus) in the Bialowieza Primeval Forest, Poland.
abstract: Between April 2008 and March 2009, we analyzed the pattern of coccidian oocysts present in the feces of the European bison (Bison bonasus L., 1758) and found 4 species (Eimeria bovis , E. canadensis, E. ellipsoidalis, E. zuernii) previously reported from this host and 3 species (Eimeria alabamensis, E. cylindrica, E. pellita) that are new host and locality records. All the species occurred in bison females, and only 4 occurred in males; E. bovis was the most prevalent in both sexes. The overall prevalence of Eimeria spp. invasion reached 34.7% in cows and 13.9% in bulls. The highest prevalence was noted in early spring, with a peak in April, and the lowest in late autumn and winter. The oocyst count per gram of feces (OPG) varied from 50 to 1,350; no symptoms of clinical coccidiosis were observed. We found a significant influence of winter aggregations of bison on shedding of coccidian oocysts. The prevalence and OPG values were higher in bison congregating in large numbers around winter-feeding sites in comparison to other sites. We suggest that the coming together of cows during the growing season impacts the gender-related differences in prevalence and the number of coccidian species involved. This observation probably results from an increased production of oocysts by sub-clinically infected individuals in high-density bison populations.
authors.affiliation: W. Stefanski Institute of Parasitology, Polish Academy of Sciences, Twarda 51/55, 00-818 Warszawa, Poland. anpyz@twarda.pan.pl
authors.forename: Anna M
authors.initials: AM
authors.lastname: Pyziel
authors.forename: Rafal
authors.initials: R
authors.lastname: Kowalczyk
authors.forename: Aleksander W
authors.initials: AW
authors.lastname: Demiaszkiewicz
mesh_terms: D000818:Animals; D016164:Bison / Q000469:parasitology*; D003048:Coccidiosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D004539:Eimeria / Q000254:growth & development / Q000502:physiology*; D005243:Feces / Q000469:parasitology*; D005260:Female; D008297:Male; D033661:Oocysts / Q000254:growth & development / Q000502:physiology; D010270:Parasite Egg Count / Q000662:veterinary; D011044:Poland / Q000453:epidemiology; D015995:Prevalence; D012621:Seasons; D017678:Sex Distribution