1. Shikoku Veterinary Medical Center, 3308–5 Ikenobe, Miki-cho, Kita-gun, Kagawa 761–0701, Japan
2. Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1–1–1 Yayoi, Bunkyo-ku, Tokyo 113–8657, Japan
3. North Labo, 8–35 2-chome-kita, Hongo, Shiroishi-ku, Sapporo-shi, Hokkaido 003–0027, Japan