1. Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616, USA
2. Department of Biological Sciences, California State University, Sacramento, California 95670, USA
3. Center for Companion Animal Health, School of Veterinary Medicine, University of California, Davis, California 95616, USA
4. Wildlife Investigations Laboratory, California Department of Fish and Game, Rancho Cordova, California 95670, USA