1. Nagasaki Prefectural Isahaya Meat Inspection Center, 79–20 Saiwai-machi, Isahaya, Nagasaki 854–0022, Japan
2. Laboratory of Veterinary Pathology, Faculty of Applied Biological Sciences, Gifu University, 1–1 Yanagido, Gifu 501–1193, Japan
3. Comparative Cancer Center, Faculty of Applied Biological Sciences, Gifu University, 1–1 Yanagido, Gifu 501–1193, Japan