1. Hirakawa Zoological Park, 5669-1 Hirakawa-cho, Kagoshima-shi, Kagoshima 891-0133, Japan
2. Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
3. The Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso-shi, Ibaraki 303-0043, Japan
4. Department of Pet Science and Technology, Shandong Vocational Animal Science and Veterinary College, Weifang 261061, Shandong Province, China