1. Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
2. Division of Infectious Diseases, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan
3. Sing-Wang of Animal Hospital, Taichung, Taiwan
4. Laboratory Animal Service Center, Office of Research and Development, China Medical University, Taichung 40402, Taiwan