1. Department of Forest and Wildlife Ecology, University of Wisconsin—Madison, Madison, Wisconsin 53706, USA
2. Current address: Damien O. Joly, Global Health Program, Wildlife Conservation Society, 1008 Beverly Drive, Nanaimo, British Columbia V9S 2S4, Canada
3. US Geological Survey—Wisconsin Cooperative Wildlife Research Unit, University of Wisconsin—Madison, Madison, Wisconsin 53706, USA
4. Wisconsin Department of Natural Resources, 2801 Progress Road, Madison, Wisconsin 53716, USA
5. University of Wisconsin, Wisconsin Veterinary Diagnostic Laboratory, 445 Easterday Lane, Madison, Wisconsin 53706, USA