1. Division of Veterinary Surgery, Department of Veterinary Science, Faculty of Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Tokyo, Japan
2. Division of Veterinary Microbiology, Department of Veterinary Science, Faculty of Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Tokyo, Japan
3. Laboratory of Veterinary Surgery, School of Veterinary Medicine, Azabu University, Chuou-ku, Sagamihara, Japan