1. Aoba Animal Hospital, 92-1 Aoba, Miyazaki, Miyazaki 880-0842, Japan
2. Division of Animal Medical Research, Hassen-kai, 2-27 Onozaki, Saito, Miyazaki 881-0012, Japan
3. Department of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1, Bunkyo-ku, Tokyo 113–8657, Japan