1. Department of Veterinary Clinical Sciences College of Veterinary Medicine Iowa State University 1800 Christensen Drive Ames IA 50011 USA
2. Department of Biomedical Sciences Oregon Veterinary Diagnostic Laboratory Carlson College of Veterinary Medicine Oregon State University 134B Magruder Hall Corvallis OR 97331 USA
3. Department of Veterinary Pathology College of Veterinary Medicine Iowa State University 1800 Christensen Drive Ames IA 50011 USA