1. Department of Dermatology, Hokkaido University Graduate School of Medicine, Kita15 Nishi7, Kita-ku, Sapporo, Hokkaido 060–8638, Japan
2. Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita18 Nishi9, Kita-ku, Sapporo, Hokkaido 060–0818, Japan