1. Laboratory of Veterinary Pathology, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
2. Comparative Cancer Center Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
3. Division of Animal Experiment, Life Science Research Center, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
4. Furuhashi Animal Hospital, 2-7-20 Kagoya, Ichinomiya, Aichi 494-0002, Japan