1. Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
2. Current address: Upstate Veterinary Specialists, Greenville, SC, USA
3. Center for Comparative Epidemiology, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
4. Department of Pathobiology and Diagnostic Investigation, and the Diagnostic Center for Population and Animal Health, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA