1. Animal Medical Center, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
2. Laboratory of Veterinary Imaging, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
3. Veterinary teaching hospital, Kagoshima University, Kagoshima, Kagoshima 890-0065, Japan
4. Laboratory of Veterinary Toxicology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan