1. Polar Knowledge Canada, Canadian High Arctic Research Station, 1 Uvajuq Road, PO Box 2150, Cambridge Bay, Nunavut X0B 0C0, Canada
2. Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7036, 750 07 Uppsala, Sweden
3. The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
4. Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada