1. College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea.
2. Department of Physiology, College of Veterinary Medicine, Konkuk University, Seoul 143-701, Korea.
3. Samsung Canine Center for Companionship (SCCC), Samsung Everland, Yongin 449-715, Korea.
4. School of Oriental Medicine, Pusan National University, Pusan 609-735, Korea.