1. Den-en-chofu Animal Hospital; 2-1-3 Denenchofu Ota-ku Tokyo 145-0071 Japan
2. Division of Pathobiological Analysis; Nippon Veterinary and Life Science University; 1-7-1 Kyonancho Musashino Tokyo 180-8602 Japan
3. Center of Animal Disease Control and Prevention; National Institute of Animal Health; 3-1-5 Kannondai Tsukuba Ibaraki 305-0856 Japan
4. Laboratory of Veterinary Pathology; Azabu University; 1-17-71 Fuchinobe, Chuo-ku Sagamihara Kanagawa 252-5201 Japan