# Evaluating the Physiologic Effects of Alfaxalone, Dexmedetomidine, and Midazolam Combinations in Common Blue-Tongued Skinks (Tiliqua scincoides)

## TL;DR

This study tested different drug combinations for sedating blue-tongued skinks and found that some combinations are safer and more effective for minor procedures.

## Contribution

The study provides the first evaluation of sedation protocols specifically for common blue-tongued skinks.

## Key findings

- All four drug combinations provided safe sedation, but ADM and AM were most effective.
- DM and ADM showed the most significant decreases in heart and respiratory rates.
- Analgesic effects were only observed in DM and ADM combinations.

## Abstract

Common blue-tongued skinks (Tiliqua scincoides) are popular pets due to their docile temper. Because of their popularity, they are routinely presented to veterinarians for examinations or procedures; however, to date, there has been limited research evaluating sedation protocols for this species. This study aimed to test different sedation combinations in these skinks: alfaxalone alone, alfaxalone with midazolam, dexmedetomidine with midazolam, and a combination of alfaxalone, dexmedetomidine, and midazolam. All four combinations provided safe sedation, but there were different physiologic responses noted. According to our trials, the combinations of all three drugs or alfaxalone with midazolam are recommended for minor procedures.

Common blue-tongued skinks (Tiliqua scincoides) are popular pet reptiles; however, there has been limited research to investigate sedatives for this species. The purpose of this study was to measure the physiologic effects of four combinations of alfaxalone, dexmedetomidine, and midazolam for minor procedures such as intubation and blood collection. Eleven common blue-tongued skinks (Tiliqua scincoides) were used for this prospective, randomized cross-over study. The subcutaneous combinations were used as follows: 20 mg/kg alfaxalone (A); 10 mg/kg alfaxalone and 1 mg/kg midazolam (AM); 0.1 mg/kg dexmedetomidine and 1 mg/kg midazolam (DM); and 5 mg/kg alfaxalone, 0.05 mg/kg dexmedetomidine, and 0.5 mg/kg midazolam (ADM). Heart rate, respiratory rate, palpebral reflex, righting reflex, escape reflex, toe pinch withdrawal reflex, tongue flicking, and the possibility of intubation were recorded at baseline and every 5 min for 60 min. Venous blood gases were measured at baseline, full sedation, and recovery. Heart and respiratory rates decreased significantly in all groups, but the reductions were most prominent in DM and ADM. Analgesic effects, as measured by the toe pinch withdrawal reflex, were only observed in DM and ADM. Intubation was possible in all four protocols; however, it was not possible in two DM skinks. Based on these trials, ADM and AM are recommended for minor procedures in blue-tongue skinks.