Assessment of the Effects of Three Doses of Intravenous Alfaxalone on Yearling Loggerhead Sea Turtles (Caretta caretta)
Alfaxalone is a neurosteroid anesthetic agent and GABAA receptor agonist that decreases activation of consciousness pathways.1 Intramuscular alfaxalone results in smooth anesthetic inductions and recoveries and dose dependent sedation in reptiles.2-4 Various anesthetic protocols have been evaluated in sea turtles, but undesirable anesthetic effects may still occur.5-7 This study compared physiologic parameters and anesthesia in yearling loggerhead sea turtles administered three different doses of intravenous alfaxalone. Nine healthy yearling loggerhead sea turtles were used. Animals were administered alfaxalone at 3, 5, and 10 mg/kg intravenously with a 7-day washout period between each anesthesia trial. Endotracheal intubation was accomplished in all animals. Venous blood gas analysis was evaluated at 0 and 30 minutes. Assisted ventilation was performed if apnea persisted 30 minutes following induction. All doses produced anesthesia. Median induction time for each group was 2 minutes. Heart rate increased in the 3 and 5 mg/kg dose groups. In the 3, 5, and 10 mg/kg dose groups, the median times to first spontaneous respiration were 16, 22, and 54 minutes and median times to recovery were 28, 46, and 90 minutes, respectively. Assisted ventilation was required in one 5 mg/kg and 5/9 10 mg/kg dose group animals. The 10 mg/kg dose group had respiratory acidosis and hypoxemia at 30 minutes. Intravenous alfaxalone administration to loggerhead sea turtles resulted in a rapid anesthetic induction and dose dependent duration of sedation. The 10 mg/kg dose resulted in prolonged apnea, which produced respiratory acidosis and marked hypoxemia, therefore assisted ventilation is recommended at that dose.
Funding provided by the Support for Aquatic Animal Medicine Fund, North Carolina State University Veterinary Medical Foundation. The authors extend their gratitude to the following individuals for their technical assistance: Michele Lamping (North Caroline Aquariums); Drs. Julie Balko, Melanie Jarret, and Sarah Cannizzo (North Carolina State University College of Veterinary Medicine); and Heather Broadhurst, Emily Barnett, Lauran Huffstetler, and Johanna Woods (North Carolina State University Center for Marine Sciences and Technology). We also thank Brad O'Hagan (Jurox Pty Ltd.) for his support and assistance with this research.
* Presenting author
+ Student presenter
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