Author's Organization:Department of Veterinary Physiology, Obihiro University, School of Veterinary Medicine Aburahi Laboratories, Shionogi & Co., Ltd. Aburahi Laboratories, Shionogi & Co., Ltd. Aburahi Laboratories, Shionogi & Co., Ltd. Department of Parasitology, Fujita-Gakuen Health University School of Medicine Department of Veterinary Physiology, Obihiro University, School of Veterinary Medicine