1. Department of Veterinary Pathology, School of Veterinary Medicine, Kitasato University, 23–35–1, Higashi, Towada, Aomori 034–8628, Japan
2. Gori Animal Hospital, Yasuhara 1–1–8, Hirosaki, Aomori 036–8162, Japan
3. Department of Veterinary Pathology, Faculty of Veterinary Medicine, Mahanakorn University of Technology, 140 Cheum-Sampan Rd, Nong-Chok, Bangkok 10530, Thailand