1. Laboratory of Farm Animal Internal Medicine, School of Veterinary Medicine, Azabu University, 1–17–71 Fuchinobe, Chuou-ku, Sagamihara, Kanagawa 252–5201, Japan
2. Laboratory of Molecular Biology, School of Veterinary Medicine, Azabu University, 1–17–71 Fuchinobe, Chuou-ku, Sagamihara, Kanagawa 252–5201, Japan
3. Kanagawa Agricultural and Mutual Aid Association, 43-2 Kamikasuya, Isehara, Kanagawa 259-1141, Japan
4. Laboratory of Small Animal Clinics, Veterinary Teaching Hospital, Azabu University, 1–17–71 Fuchinobe, Chuou-ku, Sagamihara, Kanagawa 252–5201, Japan