The combination of intratesticular and intrafunicular injection of lidocaine with general anesthetics during equine castration is able to produces a cheapest, rapid, easily technique without side effects and attenuated the post castration pain by blocking of sensory nociceptors and reduction of nociception (19-21).Recently also mepivacaine is used for local anaesthesia during equine castration (22) as it has a rapid onset, longer lasting activity, lower tissue irritation and relatively low toxicity (23, 24).Castration is a frequently performed operation in equine practice under effect of local or general anaesthesia. There are several studies that described the surgical techniques of equine castration such as (7, 25) described the open castration with second intension healing. (25, 26) described the closed and half closed castration with primary intension healing by scrotal or inguinal approach in standing or in dorsal or lateral recumbency. The inguinal approach castration with a primary intension healing in horses has a lower complication rate compared to the aforementioned techniques (26). This study was delineated to evaluate the sedative and analgesic effect of xylazine, diazepam, ketamine and propofol in donkeys that subjected to open uncovered inguinal castration with a primary intension.
Moreover, the information about pain assessment and management in donkeys is limited; therefore, this study also was performed to evaluate the hypoalgesic effect scale of adding local mepivacaine to the used anaesthetic protocol during castration by measurement of HGS and EQUUS-COMPASS.