Approximately 95% of the world’s donkeys live in developing countries are used in agriculture field or as draft animals (1). They are exposed to the different surgical interventions which elicited a painful condition such as musculoskeletal disorders, and wounds (2). Currently, the identification and detection of the specific pain behaviors in the donkey are not fully understood. The effectiveness of analgesics is measured by the response of animals and changes of the pain behavioural response (3-5).
There were a few studies that concerned with the pharmacokinetic or pharmacodynamic of the analgesics during visceral or somatic pain in donkeys, unlike horses. The specific pain behaviors in working donkey were analyzed in recent study to improve the animal’s welfare and management of pain (4).
Pain management in the donkey depends on using of multi-model analgesic to inhibit the inflammatory cascade. It is challenging to find the optimal field anesthetic regimen in a donkey which is able to overcome the fatality rate and produce a balanced anesthetic combination with profound analgesia (6, 7).
Alpha 2 agonist is the sedative and hypoalgesic drugs that used during a sedation of equine such as xylazine which has a short analgesic duration 15–20 min in donkeys and its dose (0.06 up to 1.1 mg kg-1) is similar to horses (8).
Many anaesthetic combinations had been used in donkeys, to name a few; the intermittent bolus of xylazine/ketamine every 10 min or a triple drip combination of xylazine, ketamine and guaifenesin. (9-11). Added diazepam to ketamine during anaesthesia induction in donkeys to decrease the risk of cardiopulmonary depression and prolong the anaesthesia duration with smooth recovery (12, 13).
Propofol has a longer induction time and higher metabolism compared to thiopental so that it has either no accumulative or apneic effect besides, it produces a smooth recovery (7, 14). Using a sedative dose of xylazine followed by ketamine/ propofol produced better induction and good muscle relaxation with longer duration of anesthesia and smooth recovery in donkeys than a used ketamine or propofol alone (14, 15). The sedative dose of xylazine followed by diazepam, ketamine was able to enhance the quality of anaesthesia for a short duration in donkeys (12). The continuous infusion rate of anaesthetic drugs is used safely to maintain anaesthesia with lower anaesthetic dose and to produce more hemodynamic stability in donkeys (16-18).