1. Veterinary Diagnostic Laboratory, Iowa State University, Ames, IA 50011
2. Veterinary Medical Research Institute, Iowa State University, Ames, IA 50011
3. National Veterinary Services Laboratories, Veterinary Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ames, IA 50010
4. Fairmont Veterinary Clinic, Fairmont, MN 56031