1. Department of Veterinary Clinical Sciences, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Inada Cho, Hokkaido, Japan.
2. United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.
3. Okayama Prefectural Institute for Environmental Science and Public Health, Okayama, Japan.
4. National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Inada Cho, Japan.