Sedative and cardiorespiratory effects of low doses of xylazine with and without acepromazine in Nordestino donkeys.
Authors: Lucas Castillo J A, Gozalo-Marcilla M, Werneck Fonseca M, Possebon F S, da Rosa A C, de Araujo Aguiar A J
Journal: Equine veterinary journal
Summary
# Editorial Summary: Sedation Protocols for Nordestino Donkeys Sedation regimens for donkeys remain poorly documented in the veterinary literature, particularly for endemic breeds such as the Nordestino. This randomised, blinded crossover trial evaluated four intravenous sedative protocols in seven healthy female donkeys (mean 150 kg): acepromazine alone, xylazine 0.5 mg/kg, and two combination protocols (acepromazine with either 0.25 or 0.5 mg/kg xylazine), with sedative depth and cardiorespiratory responses measured over 90 minutes. Xylazine-containing treatments produced measurable sedation within 15 minutes, evidenced by lowered head carriage and increased ataxia scores, though the combination of acepromazine with xylazine 0.25 mg/kg produced briefer sedation (15 minutes) compared with xylazine alone at 0.5 mg/kg (30 minutes of head lowering). For clinical situations requiring minimal sedation duration—such as brief procedures or examination in nervous individuals—the lower-dose acepromazine–xylazine combination may offer a practical advantage, whilst full-dose xylazine provides longer sedative cover at the cost of greater incoordination. Practitioners working with Nordestino donkeys now have preliminary guidance for dose selection, though the absence of a saline-only control group and small sample size warrant cautious interpretation of these findings.
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Practical Takeaways
- •For Nordestino donkeys requiring brief sedation, combining acepromazine 0.05 mg/kg with xylazine 0.25 mg/kg offers milder effects than higher xylazine doses while maintaining practical sedation duration
- •Expect moderate ataxia and decreased head carriage for approximately 15-30 minutes depending on xylazine dose chosen; plan handling and restraint accordingly during this window
- •Xylazine dosing in donkeys appears to follow similar principles to equines but species-specific response variation warrants careful individual assessment and documented protocols for your practice
Key Findings
- •Xylazine 0.5 mg/kg alone (SX0.5) produced head lowering for 30 minutes, while acepromazine + xylazine 0.25 mg/kg (AX0.25) produced head lowering for only 15 minutes
- •All xylazine-containing treatments increased visual analogue scale (VAS) scores and ataxia for 15 minutes post-administration with no significant differences between groups
- •Adding acepromazine 0.05 mg/kg to xylazine 0.25 mg/kg produced briefer and milder sedation compared to xylazine 0.5 mg/kg alone
- •Ataxia scores were significantly higher in SX0.5 and AX0.5 groups compared to acepromazine-only controls at 15-30 minutes post-administration