1. Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
2. Wisconsin Veterinary Diagnostic Laboratory, University of Wisconsin, Madison, WI, USA
3. Department of Biomedical Sciences, Section of Anatomic Pathology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
4. Athens Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Georgia, Athens, GA, USA