1. Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, Tokyo, Japan
2. Department of Clinical Veterinary Medicine, Division of Veterinary Research, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido, Japan
3. Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
4. Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, Tokyo, Japan;, Email: ryo@vet.ne.jp