1. Research Institute of Biosciences, Azabu University, 1–17–71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252–5201, Japan
2. Animal Specialist Center, 1–3–2 Jindanjihigashi-cho, Chofu, Tokyo 182–0012, Japan
3. Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1–17–71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252–5201, Japan