Richard K. Stroud,¹ Charles O. Thoen,² Ruth M. Duncan<sup>3

1</sup>National Wildlife Health Laboratory, U.S. Fish and Wildlife Service, 6006 Schroeder Road, Madison, Wisconsins 53711, USA
²Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa 50011, USA
³National Wildlife Health Laboratory, U.S. Fish and Wildlife Service, 6006 Schroeder Road, Madison, Wisconsin 53711, USA