1. Department of Veterinary Pathology; School of Veterinary Medicine; Rakuno Gakuen University; 582 Bunkyodai-Midorimachi Ebetsu Hokkaido 069-8501 Japan
2. Department of Large Animal Clinical Sciences; School of Veterinary Medicine; Rakuno Gakuen University; 582 Bunkyodai-Midorimachi Ebetsu Hokkaido 069-8501 Japan
3. Department of Companion Animal Clinical Sciences; School of Veterinary Medicine; Rakuno Gakuen University; 582 Bunkyodai-Midorimachi Ebetsu Hokkaido 069-8501 Japan
4. Department of Veterinary Virology; School of Veterinary Medicine; Rakuno Gakuen University; 582 Bunkyodai-Midorimachi Ebetsu Hokkaido 069-8501 Japan
5. Department of Virology; Research Institute for Microbial Diseases; Osaka University; 3-1 Yamadaoka Suita Osaka 565-0871 Japan