Gastrointestinal helminths of arctic foxes (Alopex lagopus) from different bioclimatological regions in Greenland

Nine species of gastrointestinal helminths were recovered from 254 arctic foxes (Alopex lagopus) from 8 different localities in Greenland. Prevalences of infection with the helminth species differed from area to area: Toxascaris leonina (39-68%), Strongyloides stercoralis (0-14%), Mesocestoides lineatus (0-58%), Diphyllobothrium dendriticum (0-15%), Taenia ovis krabbei (0-70%), Cryptocotyle sp. (0-3%), Plagiorchis elegans (0-6%), and Polymorphus sp. (0-3%). Additionally, a Taenia species, which appears to be different from T. ovis krabbei, had a prevalence of 24% but only on the east coast of Greenland. In general, the composition of the helminth fauna of arctic foxes in Greenland showed distinct differences geographically. Thus, the diversity of helminth species in foxes caught in the northern districts of Greenland seems lower than in the southern districts; only nematode species with direct life cycles were represented equally in all parts of the country. The diversity of the surrounding fauna, and thereby the food items available for the foxes, seems to determine the spectrum of helminth species. Helminths requiring rodents as intermediate hosts were absent on the west coast, even in the areas in northwest Greenland in close proximity to the Canadian Archipelago. Foxes from air bases, which are known to feed intensively on garbage, harbored similar numbers of species compared to foxes from settlements in the same regions. The number of T. leonina in animals less than 1 yr of age was significantly higher than in older individuals. For M. lineatus, the prevalence of infection was found to increase and worm burdens to decrease with increasing host age. Infections with 2 or more helminth species were most frequent in older animals (47% in foxes greater than or equal to 4 yr old and 33% in foxes <4 yr old).