1. Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
2. Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
3. Department of Veterinary Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
4. Health Sciences Center, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada