1. Laboratory of Veterinary Pathology, Department of Veterinary Medicine, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
2. Koizumi Nest Animal Hospital, 3-24 Betto, Yahata Nishi, Kitakyushu, Fukuoka 806-0062, Japan
3. Laboratory of Veterinary Microbiology, Department of Veterinary Medicine, Nihon University, Fujisawa, Kanagawa 252-0880, Japan