1. Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido 060-0818, Japan
2. Organization for Promotion of Tenure Track, University of Miyazaki, Miyazaki 889-2192, Japan
3. Veterinary Teaching Hospital, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido 060-0819, Japan