Efficacy, Safety, and Post-Operative Complications of Three Anesthetic Protocols for Ovariohysterectomy in Rabbits

Abstract

Introduction: Rabbits are sensitive to anesthesia and prone to perioperative complications, such as cardiorespiratory depression and hypothermia. Choosing a safe, effective anesthetic protocol is essential for surgeries such as ovariohysterectomy. The present study aimed to evaluate and compare the efficacy and safety of three anesthetic protocols, including ketamine, xylazine-ketamine, and diazepam-ketamine, in rabbits undergoing ovariohysterectomy.
Materials and methods: Forty-five young adult female rabbits aged 7-12 months and weighing 0.5-1.9 kg were used in this study. Rabbits were randomly divided into three treatment groups, with 15 rabbits in each group. Each rabbit was considered one biological replicate; therefore, each treatment group had 15 biological replicates. The first group received ketamine at 60 mg/kg of body weight (BW), the second group received xylazine and ketamine (xylazine at 3 mg/kg with ketamine at 35 mg/kg of BW), and the third group received diazepam-ketamine (diazepam at 1.0 mg/kg with ketamine at 25 mg/kg of BW) by intramuscular injection. Anesthetic indices, including onset of loss of righting reflex (OLRR), onset of analgesia (OA), and duration of analgesia (DA), were recorded. Heart rate, respiratory rate, and rectal temperature were measured at 10-minute intervals for 60 minutes. Post-operative complications, including anorexia, hypotension, hypoxemia, hyperthermia, hypothermia, self-trauma, ataxia, delayed recovery, gastrointestinal stasis, bloat, infection, and death, were monitored for 15 days.
Results: Ketamine produced the fastest OLRR at 3.59± 0.106 minutes. The xylazine-ketamine group produced the longest DA at 70.60 ± 1.501 minutes. The xylazine-ketamine group demonstrated progressive cardiovascular, respiratory, and thermoregulatory depression, including declining heart rate ( 171.13 ± 0.52 bpm ), reduced respiratory rate (55.53 ± 0.26 bpm), and hypothermia (36.33 ± 0.80 °C). The diazepam-ketamine group demonstrated moderate physiological changes with comparatively stable body temperature (38.5 ± 0.11°C). Anorexia was the most common post-operative complication across all groups. Bloat was most frequent in the ketamine group, followed by the xylazine-ketamine group.
Conclusion: Ketamine was suitable for short procedures requiring rapid induction and relative physiological stability, such as neutering, dental scaling, tooth extraction, and catheterization. Xylazine-ketamine provided prolonged analgesia but required careful cardiovascular, respiratory, and thermal monitoring. Diazepam-ketamine offered a more physiologically balanced response.