1. Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan , Saskatoon, Saskatchewan, S7N 5B4 , Canada
2. Centre for Applied Epidemiology, Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan , Saskatoon, Saskatchewan, S7N 5B4 , Canada
3. Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan , Saskatoon, Saskatchewan, S7N 5B4 , Canada