1. Department of Renewable Resources, University of Alberta, Edmonton T6G 2G7, Canada
2. Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton T6G 2M8, Canada
3. Canadian Wildlife Health Cooperative Western Northern, University of Saskatchewan, Saskatoon S7N 5B4, Canada
4. Ministry of Environment, Government of Saskatchewan, Saskatoon S7N 3R3, Canada
5. North Dakota Game and Fish Department, Bismarck, North Dakota 58501-5095, United States