1. Laboratory of Veterinary Pharmacology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183–8509, Japan
2. Hamanaka Livestock Clinic, Hokkaido East Agricultural Mutual Aid Association, Akkeshi, Hokkaido 088–1361, Japan
3. Meiji Seika Pharma, Co., Ltd., Chuo, Tokyo 104–8002, Japan