Comparison of two injectable anaesthetic protocols in Egyptian fruit bats (Rousettus aegyptiacus) undergoing gonadectomy

Abstract

Egyptian fruit bats have gained increasing interest being a natural reservoir for emerging zoonotic viruses. Anaesthesia is often required to allow safe handling of bats. We aimed to compare the sedative and cardiopulmonary effects of two balanced anaesthetic protocols in bats undergoing gonadectomy. Group DK (n = 10) received intramuscular dexmedetomidine (40 µg/kg) and ketamine (7 mg/kg), whereas group DBM (n = 10) received intramuscular dexmedetomidine (40 µg/kg), butorphanol (0.3 mg/kg) and midazolam (0.3 mg/kg). Induction time and cardiopulmonary parameters were recorded. If anaesthetic plan was inadequate, isoflurane was titrated-to-effect. At the end of surgery venous blood gas analysis was performed and atipamezole or atipamezole-flumazenil was administered for timed and scored recovery. In DBM group heart rate and peripheral oxygen saturation were significantly higher (p = 0.001; p = 0.003 respectively), while respiratory rate was significantly lower (p = 0.001). All bats required isoflurane supplementation with no significant differences between groups. Induction and recovery times showed no significant differences. In group DK a better recovery was scored (p = 0.034). Sodium and chloride were significantly higher in DBM group (p = 0.001; p = 0.002 respectively). Both anaesthetic protocols were comparable and can be recommended for minor procedures in bats.

Anesthesia, pain management and surgical approach of ovariectomy or orchiectomy in six Egyptian fruit bats (Rousettus aegyptiacus): A case report

“…Several injectable anesthetics were described in bats for various procedures; however, specific controlled studies are relatively sparse. In bats, medetomidine- or dexmedetomidine-based protocols were reported to provide deep sedation or anesthesia ( 1 , 8 , 10 , 11 ). Alpha-2-adrenergic agonists tend to produce significant effects on the cardiovascular system (initial hypertension, profound reflex bradycardia and poor peripheral circulation) ( 11 , 33 , 34 ), therefore, they were avoided in the present report.…”

“…Although not reported in bats, the authors applied local anesthetic techniques previously reported in other species during gonadectomies ( 31 , 32 ), to provide better analgesia and to increase animal welfare. Although locoregional techniques were not used by Amari et al it was recommended by the authors for bat gonadectomies ( 10 ).…”

“…Alfaxalone-midazolam-morphine protocol in the present report produced higher HR than dexmedetomidine-based protocols (DK 181 ± 31 bpm; DBM 203 ± 47 bpm). However, f R was lower (DK 112 ± 26 rpm; DBM 85 ± 21 rpm) ( 10 ). Although bats were actively warmed during surgery, the immediate postoperative rectal temperature was below 36.5 °C, which is the average normal rectal temperature reported for R. aegyptiacus ( 36 ).…”

“…Alpha-2-adrenergic agonists were reported in bat species and are usually combined with other drugs, such as ketamine, opioids and/or benzodiazepines ( 1 , 8 , 10 , 11 ). A recent study compared dexmedetomidine-butorphanol-midazolam (0.04–0.3–0.3 mg/kg; DBM) and dexmedetomidine-ketamine (0.04–7 mg/kg; DK) in R. aegyptiacus undergoing gonadectomy ( 10 ).…”

“…In fruit bats, a ventral midline approach to ovariohysterectomy was reported ( 10 ). However, it may lead to self-mutilation and evisceration.…”