[1] Tokyo Univ Agr & Technol, Fac Agr, Dept Vet Surg, Cooperat Dept Vet Med, Fuchu 1838509, Japan
[2] Okayama Univ Sci, Fac Vet Med, Lab Vet Anat, Imabari 7948555, Japan
[3] Tokyo Univ Agr & Technol, Fac Agr, Dept Vet Surg, Cooperat Dept Vet Med, 3-5-8 Saiwai, Fuchu 1838509, Japan