1. School of Veterinary Medicine, University of Wisconsin–Madison, Madison, Wisconsin, USA
2. Wisconsin Veterinary Diagnostic Laboratory, Madison, Wisconsin, USA
3. National Veterinary Services Laboratories, Veterinary Services, U.S. Department of Agriculture, Ames, Iowa, USA
4. IDEXX Laboratories, Inc., West Sacramento, California, USA
5. California Animal Health and Food Safety Laboratory, University of California, Davis, Davis, California, USA
6. Animal Care Centers of New York City, New York, New York, USA
7. Southeast Poultry Research Laboratory, Athens, Georgia, USA