1. William R. Pritchard Veterinary Medicine Teaching Hospital, School of Veterinary Medicine, University of California Davis Davis California USA
2. Department of Clinical Sciences College of Veterinary Medicine and Biomedical Sciences, Colorado State University Fort Collins Colorado USA
3. Department of Surgical and Radiological Science School of Veterinary Medicine, University of California Davis Davis California USA
4. Department of Medicine and Epidemiology School of Veterinary Medicine, University of California Davis Davis California USA
5. Department of Clinical Sciences College of Veterinary Medicine, North Carolina State University Raleigh North Carolina USA