1. Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
2. Japan Small Animal Medical Center, 2-27-4 Nakatomi-minami, Tokorozawa, Saitama 359-0003, Japan
3. Japan Animal Referral Medical Center, 2-5-8 Kuji, Takatsu-ku, Kawasaki, Kanagawa 213-0032, Japan
4. 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