Comparison of Two Anesthesia Protocols for Celioscopic Sexing in Juvenile Blanding’s Turtles (Emydoidea blandingii)
The isolated population of Blanding’s turtles (Emydoidea blandingii) in Nova Scotia has been designated as threatened since 1993.1 Living at the northern periphery of the species’ range, this population is considered particularly vulnerable due to cold temperatures prolonging incubation time, potentially skewing sex ratio towards males, and decreasing breeding success.1
Two anesthesia protocols were compared in a group of two-year-old Nova Scotia Blanding’s turtles undergoing celioscopic sexing as a part of a conservation project. Ninety-four turtles were randomly attributed to one of the two following protocols: morphine (0.5 mg/kg)/dexmedetomidine (0.05 mg/kg)/ketamine (10 mg/kg) IM or butorphanol (0.5 mg/kg)/dexmedetomidine (0.05 mg/kg)/ketamine (10 mg/kg) IM. Only the dexmedetomidine was reversed after the procedure. Body weight, carapace length, as well as duration and ease of coelioscopy, did not differ statistically between the two groups. Induction and recovery times were also not statistically different between protocols. Level of anesthesia was significantly deeper in the turtles who received the morphine protocol. However, three turtles from the morphine group died postoperatively. The first case of mortality was due to an anaphylactic reaction. The two additional mortalities were suspected to be caused by impaired ability to thermoregulate.
While the morphine protocol provided a deeper level of anesthesia, morphine increased the risk of postanesthetic mortality in Blanding’s turtles. Turtles should be monitored closely if morphine is used as they appear to be a heat-sensitive species.
The authors thank Dr. Henrik Stryhn for statistical assistance as well as the students and staff for assistance with the turtles.
1. Standing KL, Herman TB, Morrison IP. Nesting ecology of Blanding’s turtle (Emydoidea blandingii) in Nova Scotia, the northeastern limit of the species’ range. Can J Zool. 1999;77:1609–1614.