Affiliation: | (1) Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan, JP;(2) Virology Section, Hokkaido Institute of Public Health, Sapporo, Japan, JP;(3) Veterinary Teaching Hospital, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan, JP;(4) Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan, JP |