Comparative Analysis of Anesthesia Induction in Red-Eared Sliders (Trachemys scripta elegans) by Two Different Administration Routes and Doses of Ketamine and Medetomidine

The growing popularity of turtles as pets has led to increased demand for veterinary care for these animals. Reptile anesthesia can be challenging, and ketamine in combination with medetomidine administered intramuscularly or intravenously can lead to superficial anesthesia. This study aimed to assess the efficiency of ketamine and medetomidine by two different doses and routes on anesthesia depth and cardiac stability in red-eared sliders.
The study was conducted at the Veterinary Faculty - University of Sarajevo. Each turtle was anesthetized two times, with seven days wash-out period. Induction of anesthesia consisted of a bolus combination of ketamine (10 mg/kg) and medetomidine (0.2 mg/kg) administered in the left brachial biceps in the intramuscular protocol, or a bolus combination of ketamine (20 mg/kg) and medetomidine (0.2 mg/kg) administered in subcarapacial sinus after clear blood presence confirmation in the intravenous protocol. Vital signs, reaction on the skin palpation, manual mouth opening for endotracheal intubation, palpebral and cloacal reflex, and the withdrawal reflex of the front and hind limbs were measured and recorded every 5 minutes for 60 minutes after anesthesia injection. Atipamezole (1 mg/kg) was administered in the right brachial biceps one hour after ketamine and medetomidine administration. Needle insertion and possible painful reactions to drug administration were also evaluated and recorded. Obtained data were analyzed for normality and paired t-tests, Wilcoxon, or McNamar tests were performed where appropriate. The values of P
0.05 were considered significant. The surgical plane of anesthesia was achieved 100% and 5% in intravenous and intramuscular anesthesia protocols, respectively. A significantly less pronounced decrease in heart rate was observed with intravenous anesthesia protocol, while a decrease below 30% of basal heart rate was observed in 95% of animals in intramuscular anesthesia protocol. Both protocols recorded complete anesthesia recovery 60 minutes after intramuscular atipamezole administration. A ketamine-medetomidine dose combination administered intravenously provides a more stable and consistent anesthetic plane in red-eared sliders than ketamine-medetomidine administered intramuscularly. Therefore, intravenous administration of this combination should be the preferred route for inducing surgical plane anesthesia in this animal species.