1. Department of Veterinary Biomedical Sciences; Western College of Veterinary Medicine; 52 Campus Drive, University of Saskatchewan Saskatoon SK Canada S7N 5B4
2. Department of Veterinary Clinical Medicine; University of Cambridge; Madingley Road Cambridge CB3 0ES
3. Department of Clinical Sciences; College of Veterinary Medicine, North Carolina State University; Raleigh NC 27606 USA