1. Department of Environment and Natural Resources, Government of the Northwest Territories, Box 900, Fort Smith, Northwest Territories X0E 0P0, Canada
2. Current address: 2231 Clarence Avenue South, Saskatoon, Saskatchewan S7J 1L6, Canada
3. Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada
4. Department of Environment and Natural Resources, Government of the Northwest Territories, Box 240, Fort Simpson, Northwest Territories Z0E 0N0, Canada
5. Department of Environment and Natural Resources, Government of the Northwest Territories, 500-5102 50th Avenue, Yellowknife, Northwest Territories X1A 3S8, Canada
6. Department of Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada