Problems associated with perioperative morphine in horses: a retrospective case analysis

Area of Science:

• Veterinary Anesthesiology
• Equine Surgery
• Pharmacology

Background:

• Perioperative analgesia is crucial for equine welfare during surgical procedures.
• Morphine is a commonly used opioid for pain management in horses.
• Understanding the incidence of adverse effects associated with morphine administration is essential for safe anesthetic protocols.

Purpose of the Study:

• To determine the incidence of adverse effects following morphine administration (100-170 micro g kg-1) during equine surgery.
• To evaluate the safety and efficacy of morphine as a perioperative analgesic in horses.

Main Methods:

• Retrospective analysis of anesthetic records from 1996-2000.
• Inclusion of 84 healthy horses (ASA 1 or 2) undergoing laryngeal surgery or orchiectomy.
• Comparison of physiological data and complication incidence between horses receiving morphine (M+) and those not receiving it (M-).

Main Results:

• No significant differences in physiological parameters (heart rate, respiratory rate, mean arterial pressure) were observed between groups.
• The incidence of intraoperative and post-operative complications, including box-walking and colic, was similar in both morphine and non-morphine groups.
• Recovery scores did not differ significantly between the M+ and M- groups.

Conclusions:

• Morphine at doses of 100-170 micro g kg-1 does not elevate the risk of adverse events in horses undergoing anesthesia with romifidine, ketamine, diazepam, and halothane.
• Morphine is a safe and cost-effective option for perioperative analgesia in horses.
• The findings support the continued use of morphine for pain management in equine surgical patients.