1. Department of Veterinary Surgery, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3–5–8 Saiwai-cho, Fuchu, Tokyo 183–8509, Japan
2. Department of Veterinary Clinical Oncology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3–5–8 Saiwai-cho, Fuchu, Tokyo 183–8509, Japan
3. Laboratory of Veterinary Internal Medicine, Faculty of Veterinary, Nippon Veterinary and Life Science University, 1–7–1 Kyounan-cho, Musashino, Tokyo 180–8602, Japan
4. Animal Clinical Research Foundation, 214–10 Yatsuya, Kurayoshi, Tottori 682–0025, Japan