1. Equine Science Division, Hidaka Training and Research Center, Japan Racing Association, 535–13 Nishicha, Urakawa-cho, Urakawa-gun, Hokkaido 057–0171, Japan
2. Ritto Training Center, Japan Racing Association, Misono 1028, Ritto-shi, Shiga 520–3005, Japan
3. Miho Training Center, Japan Racing Association, Mikoma 2500–2, Miho-mura, Inashiki-gun, Ibaraki 300–0415, Japan
4. Department of Domestic Animal Internal Medicine, Clinical Veterinary Science, Veterinary Medicine, Joint Faculty of Veterinary Medicine, Kagoshima University, 1–21–24 Korimoto, Kagoshima-shi, Kagoshima 890–0065, Japan