Effects of epidural, spinal, and combined spinal-epidural anesthesia on cardiorespiratory variables and postoperative analgesia in dogs undergoing ovariohysterectomy

Articles in Press

Document Type : Research Article

Authors

Maedeh Javaheri ¹

Hadi Imani Rastabi ¹

Masoumeh Ezzati Givi ²

Bahman Mosallanejad ¹

¹ Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.

² Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran

10.22067/ijvst.2026.98955.1664

Abstract

Epidural and spinal anesthesia are frequently used in small animals, although they may also cause undesirable side effects. A combined spinal-epidural approach might reduce individual drug doses and yield more favorable outcomes. This prospective, randomized, blinded study compared the cardiorespiratory effects and analgesic efficacy of epidural, spinal, and a combined spinal-epidural technique in dogs undergoing ovariohysterectomy. Nineteen healthy mongrel dogs were premedicated with acepromazine and morphine, induced (6 mg/kg) and maintained (0.4 mg/kg/min) with propofol. Dogs then received bupivacaine through epidural (1 mg/kg with a final volume of 0.35 mL/kg, n = 6), spinal (0.22 mg/kg with a final volume of 0.16 mL/kg, n = 7), or a combined epidural and spinal anesthesia (n = 6). For the Combination, equal volumes and half the doses were used. Physiologic variables, recovery times, and pain scores were recorded at predetermined intervals. In all groups, heart rate increased during surgery, while mean arterial pressure decreased below baseline at several time points. Pain scores did not differ significantly among treatments, and all three techniques provided acceptable perioperative analgesia. Postoperatively, rescue fentanyl was administered to two dogs in the spinal group and two in the Combination group, with no significant difference among groups. Shorter times to head elevation and standing were observed in the Combination group compared with the epidural group. Overall, the combined spinal-epidural approach may provide comparable cardiorespiratory stability with effective analgesia and faster recovery, proposing it as a useful option for dogs undergoing ovariohysterectomy.

Keywords

Bupivacaine

Dog

Epidural anesthesia

Ovariohysterectomy

Spinal anesthesia

Subjects

• Anesthesia and Analgesia

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