1. Department of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
2. Equine Research Institute, Japan Racing Association (JRA), Utsunomiya, Tochigi 320-0856, Japan
3. Blood Horse Training Center, JRA Foundation, Minato-ku, Tokyo 105-0001, Japan
4. Racing Museum, JRA, Fuchu, Tokyo 183-0024, Japan