1. College of Veterinary Medicine NC State University 1060 William Moore Drive Raleigh NC27607USA
2. Department of Clinical Sciences College of Veterinary Medicine NC State University 1060 William Moore Drive Raleigh NC27607USA
3. Department of Microbiology, Immunology and Pathology College of Veterinary Medicine and Biomedical Sciences Colorado State University 300 West Drake Road, Fort CollinsCO80523USA
4. Washington Animal Disease Diagnostic LaboratoryWashington State University 2607 W Pioneer Puyallup WA98371USA
5. Department of Population Health and Pathobiology College of Veterinary Medicine NC State University 1060 William Moore Drive Raleigh NC27607USA