1. Laboratory of Veterinary Pathology, Division of Veterinary Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano City, Osaka 598-8532, Japan
2. Kitasuma Animal Hospital, 9-5-8 Yokoo, Suma-ku, Kobe City, Hyogo 654-0131, Japan