Xylazine (0.35 mg/kg at a concentration of 20 mg/ml) or lidocaine (0.35 mg/kg at a concentration of 20 mg/ml) was injected into the epidural space of 6 donkeys (group 1) to compare their effectiveness as epidural analgesics. Each donkey received both treatments at one week intervals with the order of treatments randomized. Xylazine produced analgesia of significantly longer duration (226+35 minutes) than that produced by an equal doses of lidocaine (120+25 minutes).
6 donkeys (group II) were treated with epidural xylazine (0.35 mg/kg), epidural lidocaine (0.35 mg/kg) or epidural saline as a control. The treatment randomized and given to all donkeys. Baseline values (at time O) for heart rate (HR), respiratory rate (RR), Paco, were deter mined, and at, 10, 20, 30, 60 and 90 minutes post treatment. Epidural injection of saline did not alter sensory perception to needle prick and did not affect any of the physiologic parameters determined. Epidural xylazine (EX) or epidural lidocaine (EL) do not cause significant changes in HR,RR, Paco, in adult and young donkeys. This results indicted that EX and EL do not cause significant physiologic stress in donkeys. This study suggests that Ex can be considered a safe method of induc ing caudal analgesia in adult and young donkeys.