1. Department of Veterinary Medicine; National Chung Hsing University; 250 Kuo Kuang Road Taichung 402 Taiwan
2. Graduate Institute of Microbiology and Public Health; College of Veterinary Medicine; National Chung Hsing University; 250 Kuo Kuang Road Taichung 402 Taiwan
3. Veterinary Medical Teaching Hospital; National Chung Hsing University; 250 Kuo Kuang Road Taichung 402 Taiwan