1. Laboratory of Veterinary Surgery, Department of Veterinary Medicine, College of Bioresource and Sciences, Nihon University, Fujisawa, Kanagawa, Japan
2. Laboratory of Veterinary Radiology, Department of Veterinary Medicine, College of Bioresource and Sciences, Nihon University, Fujisawa, Kanagawa, Japan
3. Katsura Veterinary Hospital, Sapporo, Hokkaido, Japan
4. Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States