ABSTRACT
Xylazine, detomidine or romfidine should definitely be part of the protocol for equine anesthesia. Alpha-2 agonists provide dose-dependent sedation and mild to moderate analgesia. Although not a common addition to field anesthesia protocols, acepromazine can be used in combination with an alpha-2 agonist for premedication of horse’s anesthetized in-hospital. Opioids provide reversible analgesia and the effects are synergistic with those of the alpha-2 agonists. Opioids can be administered as a premedication with the sedatives or as part of induction. The of onset anesthesia IV ketamine is 1-2 minutes and the effects last for 20-30 minutes, which is a perfect duration for most field procedures. True muscle relaxants like the benzodiazepines and guaifenesin are also commonly added to the ketamine, especially for in-hospital procedures. Butorphanol is the most commonly used opioid in horses but morphine use is increasing. However, they provide more profound analgesia than the other alpha-2 agonists and are occasionally used as constant rate infusions during surgery.
