1. Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and The Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan
2. Department of Veterinary Pathology, School of Veterinary Medicine, Faculty of Agriculture, Tottori University, 4-101 Minami Koyama-cho, Tottori, Tottori 680-8553, Japan