1. The Department of Medical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, WA, U.S.A.
2. The Department of Preventive Medicine, College of Veterinary Medicine, University of Florida, Gainesville, WA, U.S.A.
3. The Laboratory of Comparative Thrombosis and Hemostasis, College of Veterinary Medicine, Washington State University, Pullman, WA, U.S.A.