COMPARISON OF THREE SEDATION COMBINATIONS IN ISOFLURANE-ANESTHETIZED GARDEN DORMICE (ELIOMYS QUERCINUS) UNDERGOING LAPAROTOMY.

Abstract

The garden dormouse (Eliomys quercinus) is commonly used as model species for studies on hibernation, which may involve surgery. Similar to laboratory rodents, inhalational anesthesia, which does not provide analgesia, is often performed for surgical procedures. We retrospectively compared cardiorespiratory effects between ketamine-butorphanol-medetomidine (KBMed), ketamine-butorphanol-midazolam (KBMid) and butorphanol-medetomidine-midazolam (BMM) administered SC in 48 garden dormice undergoing laparotomy for bio-logger implantation plus tissue (liver, brown fat) biopsy surgery (n = 48/48 [28 females, 20 males] ∼5 wk old) and bio-logger explantation surgery (n = 42/48 [24 females, 18 males], ∼1 yr old). Doses were ketamine (40 mg/kg), medetomidine (0.2 mg/kg), midazolam (1 mg/kg), and butorphanol (0.2 mg/kg). Anesthesia was supplemented with isoflurane (1.29 ± 0.53%) in 100% oxygen via facemask; meloxicam and lactated Ringer's solution were administered SC; and a splash block using lidocaine was performed. Sedation score and recovery time were recorded. The pedal withdrawal reflex, pulse rate, RR, SpO₂, and temperature were monitored throughout the laparotomy. The effects of group and time were tested using linear mixed-effect models, with individuals as random factor. Sedation score was the deepest with KBMed. Pulse rate, RR, and temperature remained within physiological ranges for KBMid, but were decreased with KBMed and BMM (P < 0.001). SpO₂ remained >96% in all groups. Recovery time was shortest with KBMid (20.8 ± 18.1 min); KBMed and BMM required reversal with atipamezole after 60 min, otherwise recovery time would have been prolonged. All combinations allowed for appropriate intraoperative analgesia, cardiorespiratory stability, and adequate postoperative wound healing.