Evaluating the Anesthetic and Physiologic Effects of Intramuscular and Intravenous Alfaxalone in Eastern Mud Turtles (Kinosternon subrubrum)

Abstract

Current sedation protocols for chelonians can pose a challenge to clinicians because of prolonged induction and recovery times, difficulties in gaining venous access, and natural species variation. This study evaluated the sedative and physiologic effects of intramuscular (IM) and intravenous (IV) alfaxalone in six wild-caught adult eastern mud turtles (Kinosternon subrubrum). The turtles received alfaxalone 10 mg/kg IM and IV in a randomized cross-over design. A 10-day washout period occurred between trials. Baseline parameters (heart rate, respiratory rate, temperature, and reflexes) were assessed prior to injection and every 5 min post-injection until recovery. Three venous blood gas samples were also collected and analyzed over the course of each trial (baseline, induction, and recovery). Intravenous alfaxalone resulted in a significantly faster induction (p = 0.016; median: 1.5 min, 25–75%: 1–7.5, minimum–maximum: 1–21) and a shorter total sedation time (p = 0.041; median: 52 min, 25–75%: 34.5–62.5, minimum–maximum: 33–87) when compared with IM alfaxalone (induction, median: 20 min, 25–75%: 15–22.5, minimum–maximum: 15–25; total, median: 70 min, 25–75%: 65–82.5, minimum–maximum: 65–90). Blood gas and physiologic parameters were not significantly different between groups; however, the pH (p = 0.009) and glucose (p = 0.0001) significantly increased, and partial pressure of carbon dioxide (p = 0.024) significantly decreased over time. This study demonstrated that alfaxalone 10 mg/kg IV or IM can be used to provide safe and effective sedation in eastern mud turtles.