1. Behavior Service, San Francisco SPCA Veterinary Hospital, San Francisco, CA, USA
2. Institute of Viral Diseases, Department of Microbiology, Korea University, College of Medicine, Seoul, South Korea
3. Department of Veterinary Medicine and Epidemiology, University of California, School of Veterinary Medicine, Davis, CA, USA
4. Veterinary Teaching Hospital, Chungbuk National University, College of Veterinary Medicine, Cheongju, Chungcheongbuk-do, South Korea