1. Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
2. Veterinary Diagnostic and Production Animal Medicine and Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames 50011
3. Kemptville Campus, University of Guelph, Kemptville, Ontario, Canada, K0G 1J0