Comparing the anti-nociceptive, sedative and clinicophysiological effects of epidural detomidine, detomidine-lidocaine and lidocaine in donkeys.

Background: Epidural analgesia using the alpha-2 agonist detomidine (DE), alone or in combination with lidocaine (LD), is frequently employed for standing surgical procedures in horses, but its use has not been evaluated in donkeys.
Methods: In a randomised controlled prospective trial, 24 healthy adult donkeys were assigned to four groups (n = 6), each receiving 40 μg/kg of DE, 0.22 mg/kg of LD, combined DE and LD (DELD) or 0.9% sterile normal saline epidurally. After epidural injection of each treatment, the onset, degree and duration of sedation and anatomical extension of anti-nociception were observed.
Results: DE and DELD treatments resulted in complete bilateral analgesia with loss of sensation in the tail, perineum, inguinal area, chest and the caudal aspect of the upper pelvic limb, and extended distally to the dorsal metatarsal area. DE and DELD resulted in a significantly (p < 0.05) longer duration of anti-nociception (110 ± 15.4 min and 141.6 ± 14.7 min, respectively) than LD (75.8 ± 4.9 min). The DELD duration of sedation was significantly (p < 0.05) longer than the DE duration (118.3 ± 19.4 min and 108.3 ± 7.5 min, respectively).
Limitation: The current study's main limitation is using only one dose of DE.
Conclusion: DE and DELD produced a very effective, safe and acceptable sedative and analgesic effect in the perineal and inguinal regions of donkeys.
(© 2022 British Veterinary Association.)