Sentinels in a climatic outpost: Endoparasites in the introduced muskox (Ovibos moschatus wardi) population of Dovrefjell, Norway

• Faeces from 167 muskoxen examined in a population introduced to Norway 60 years ago.
• Lungworms and intestinal helminths and protozoa were quantified.
• Cryptosporidium xiaoi and Giardia duodenalis Assemblage A were found.
• Lungworms Dictyocaulus sp. and Muellerius capillaris were identified.
• Spill-over of parasites from sympatric sheep and reindeer is likely.

We assessed the occurrence of endoparasite eggs, cysts, oocysts and larvae in the muskox population of Dovrefjell, Norway, during June and August 2012. This population originates from 13 calves translocated from Eastern Greenland during the 1950s. A total of 167 faecal samples were collected, of which 49% came from identified individuals: 165 were examined by the Baermann and 95 by McMaster techniques and 167 by immunofluorescence antibody test (IFAT). Lungworm larvae recovered in the Baermanns were identified as Protostrongylidae (82%) and Dictyocaulus sp. (76%) based on morphology. Further molecular analyses of the ITS-2 region of two protostrongylid larvae from two muskoxen as Muellerius capillaris. Larval prevalence and intensity differed significantly between samples collected from the different age groups in June and August, with increasing prevalence and intensity in calves during the course of their first summer, whereas intensity decreased in adults from June to August. McMaster test and IFAT were used to determine the occurrence of infections with intestinal strongyles (84%), Moniezia spp. (24%), Nematodirus sp. (2%), Eimeria spp. (98%), Cryptosporidium sp. (14%) and Giardia duodenalis (7%). Molecular analyses of three isolates of Cryptosporidium and Giardia were identified as Cryptosporidium xiaoi and G. duodenalis assemblage A. Although infection intensity of all these intestinal parasites tended to be low, the high level of polyparasitism, together with the other challenges faced by this population living at the edge of their climatic range, means that these infections should not be ignored. The potential that M. capillaris, Cryptosporidium and Giardia infections derive from other sympatric host species (sheep and reindeer) is discussed.

Muskox cow and calf in Dovrefjell, Norway, fresh muskox faeces showing clearly visible proglottids, IFAT staining of muskox faecal sample showing Giardia cysts.Figure optionsDownload as PowerPoint slide