1. Department of Veterinary Surgery, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.
2. Department of Veterinary Surgery, College of Veterinary Medicine, Kangwon National University, Chuncheon 24341, Korea.
3. BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science and College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.