1. Oregon Department of Fish and Wildlife, South Willamette Watershed District Office, Corvallis, Oregon 97330, USA
2. US Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison, Wisconsin 53711-6223, USA
3. Current address: Cornell University, College of Veterinary Medicine, 240 Farrier Rd., Ithaca, New York 14850, USA