1. 1 Department of Pathology and Population Medicine, Animal Health Institute, Midwestern University, Glendale, AZ
2. 2 Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL
3. 3 Department of Veterinary Teaching Hospital, College of Veterinary Medicine, University of Illinois, Urbana, IL
4. 4 Private practitioner, Momence, IL