Four sika deers (Cervus nippon) (3 males, and 1 female) with depression, loss of appetite, high body temperature and hematochezia were dead in June, 1999 and Yersinia was cultured from their pathological materials In addition, the susceptibility of Yersinia to antibiotics and the toxicity to mice were detected All the other sika deers contacted with the died animals were treated with amikacin sulfate and protected from the