1. US Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison, Wisconsin 53711, USA
2. Athens Veterinary Diagnostic Laboratory, University of Georgia, 501 D. W. Brooks Drive, Athens, Georgia 30602, USA
3. Animal Health Diagnostic Center, Cornell University College of Veterinary Medicine, 240 Farrier Road, Ithaca, New York 14850, USA
4. US Fish and Wildlife Service, Washington Fish and Wildlife Office, 510 Desmond Drive, Suite 102, Lacey, Washington 98503, USA
5. Department of Fisheries and Oceans Canada, Central and Arctic Region, 501 University Crescent, Winnipeg, Manitoba, Canada, R3T 2N6
6. US Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, Maryland 20705, USA