Transmucosal pentobarbital is a successful euthanasia method in pond slider turtles (Trachemys scripta).

Abstract

To determine the ability of transmucosal euthanasia solution to induce euthanasia in pond slider turtles (Trachemys scripta). 16 pond slider turtles (T. scripta). Pentobarbital 100 mg/kg was delivered through esophageal gavage (n = 8) or cloacal administration (8). The presence of voluntary movement, heart rate (HR), respiratory rate (RR), palpebral reflex, corneal reflex, and response to noxious stimuli were recorded until death, confirmed via the absence of reflexes, movement, heartbeat, and absence of cardiac electrical activity. No signs of irritation were observed in any turtles. Leakage after administration occurred in 75% (6/8) of the cloacal group, including 2 turtles with marked leakage or expulsion. Two of eight turtles in the cloacal group regained movement and required euthanasia by a standard method and 1 turtle in the oral group was excluded from further analysis due to a miscalculated dose. The remaining 13 turtles (7/8 oral, 6/8 cloacal) had cessation of a heartbeat at a median of 18 hours (range = 6 to 26 hours) with respiratory arrest occurring within 15 minutes. The median time to loss of corneal reflex was 45 minutes (range = 15 minutes to 4 hours). Time-to-loss of parameters was similar between oral and cloacal routes, respectively. Transmucosally administered pentobarbital via the oral and cloacal routes both result in euthanasia within approximately 24 hours. Given that 25% of the turtles in the cloacal group required a secondary method of euthanasia, the oral route is a preferred route to induce euthanasia in pond turtles.