Helminths of grizzly and black bears in Alberta and British Columbia, Canada


Stefano Catalano, Manigandan Lejeune, Paolo Tizzani, Guilherme G. Verocai, Helen Schwantje, Cait Nelson, and Pádraig J. Duignan


Canadian Journal of Zoology 93(10):765-772; 2015


Between May 2011 and June 2013, we collected the carcasses and gastrointestinal tracts of 40 American black bears (Ursus americanus Pallas, 1780) and 13 grizzly bears (Ursus arctos L., 1758) from populations of Alberta and British Columbia, Canada. Specimens were examined for helminths, which were identified to the species level by applying an integrated morphological and molecular approach. Our goal was to investigate parasite biodiversity and infection parameters in the sampled grizzly and black bears. We found seven parasite taxa: Dirofilaria ursiYamaguti, 1941, Baylisascaris transfuga (Rudolphi, 1819), Uncinaria rauschi Olsen, 1968,Uncinaria yukonensis (Wolfgang, 1956), Taenia arctos Haukisalmi, Lavikainen, Laaksonen and Meri, 2011, Diphyllobothrium dendriticum (Nitzsch, 1824), and Diphyllobothrium nihonkaienseYamane, Kamo, Bylund and Wikgren, 1986. The statistical significance of infection prevalence, intensity, and abundance for each helminth species was assessed relative to host species, gender, age class, sampling season, and location. This is the first unequivocal report of the potentially zoonotic tapeworms D. dendriticum and D. nihonkaiense in North American bears. Furthermore, we provide insight into the biology and ecology of the nematodes B. transfugaD. ursi, and species of Uncinaria Frölich, 1789, and enrich the information available on the recently described tapeworm T. arctos.