1. US Geological Survey–National Wildlife Health Center, Madison, 6006 Schroeder Road, Madison, Wisconsin 53711, USA
2. Current address: US Geological Survey National Center, 12201 Sunrise Valle Drive MS 913, Reston, Virginia 20192, USA
3. Minnesota Department of Natural Resources, Wildlife Health Program, 5463-C West Broadway, Forest Lake, Minnesota 55025, USA
4. US Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, 644 Bayfield Street, Suite 215, St. Paul, Minnesota 55107, USA