1. Asahikawa Municipal Asahiyama Zoological Park & Wildlife Conservation Center, Kuranauma, Higashiasahikawa-cho, Asahikawa, Hokkaido 078–8205, Japan
2. National Institute of Infectious Diseases, 1–23–1 Toyama, Shinjuku–ku, Tokyo 162–8640, Japan
3. Hokkaido Kamikawa Livestock Hygiene Service Center, 4–15 Higashitakasu, Asahikawa, Hokkaido 071–8154, Japan
4. Hokkaido Nemuro Livestock Hygiene Service Center, 69 Betsukaimidorimachi, Betsukai, Notsukegun, Hokkaido 086–0214, Japan
5. Department of Wildlife Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252–8510, Japan