The dose dependent effects of epidural analgesia in donkeys, and to what extent the animals can tolerate the large doses of the analgesic drug were studied. Anterior epidural analgesia of short duration was obtained after injection of 10 ml 2% procaine hydrochloride solution. The duration of analgesia and the desensitized area increased by increasing the dose. Tonic stretching of the head and neck occured when large doses (100-120 ml) were used. The chages in the heart rate and respiratory rate were obvious after epidural injection of large doses of the analgesic drug.