The effect of different immobilization approaches on red-eared sliders

The ethical issues surrounding sacrifice methods in animal experimentation have garnered increasing attention, making immobilization and sedation an integral part of the sacrifice process for experimental animals. Currently, internationally recognized general sacrifice methods for commonly used laboratory animals have been established, but there remains significant controversy over the sacrifice methods for turtles. To explore the effectiveness of various immobilization methods and their impact on stress-related indicators in turtles, this study used red-eared sliders (Trachemys scripta elegans) as subjects. Our findings indicate that - 20 °C cryoimmobilization achieved immobilization after 45 min, with individual deaths occurring after 75 min or more. When the dose of pentobarbital sodium for intraperitoneal/intramuscular injection reaches 0.02 mg/g, an anesthetic effect can be achieved, but exceeding 0.03 mg/g may lead to the death of the individual. While for ether immobilization, 60 min can achieve the anesthetic effect, a duration of over 120 min may cause the risk of hypoxia. With the exception of the ether inhalation immobilization 90min group, the 0.03 mg/g pentobarbital sodium intraperitoneal injection group and - 20 °C cryoimmobilization 45 and 60 min groups, no significant differences in brain, heart, and liver function indicators were observed between the remaining groups and decapitation sacrifice group. The administration of pentobarbital sodium injection for immobilization is relatively simple, with a short induction period, a long immobilization duration, and good anesthetic effects. In summary, pentobarbital sodium injection immobilization is a worth considering method, with an effective injection dose of 0.02 mg/g. Intramuscular injection has a shorter induction period compared to intraperitoneal injection. The research results can provide a reference for the choice of sacrifice methods for turtles.