1. Department of Veterinary Pathology; College of Veterinary Medicine and School of Agricultural Biotechnology; Seoul Natiolal University; Suwon 441-744 Republic of Korea
2. Department of Infectious Disease; College of Veterinary Medicine and School of Agricultural Biotechnology; Seoul Natiolal University; Suwon 441-744 Republic of Korea
3. Everland Zoological Gardens; Yougin Republic of Korea