1. Department of Veterinary Pathology, Nippon Veterinary and Life Science University, 1–7–1 Kyonan-cho, Musashino, Tokyo 180–8602, Japan
2. Department of Veterinary Pharmacology, Nippon Veterinary and Life Science University, 1–7–1 Kyonan-cho, Musashino, Tokyo 180–8602, Japan
3. Department of Veterinary Surgery, The University of Tokyo, 1–1–1 Yayoi, Bunkyo, Tokyo 113–8657, Japan
4. Department of Veterinary Biochemistry, Nippon Veterinary and Life Science University, 1–7–1 Kyonan-cho, Musashino, Tokyo 180–8602, Japan