Evaluation of a dexmedetomidine-midazolam-ketamine combination administered intramuscularly in captive ornate box turtles (Terrapene ornata ornata)

Objective To characterize the effects of a combination protocol of dexmedetomidine-midazolam-ketamine (DMK) administered intramuscularly (IM) in ornate box turtles (Terrapene ornata ornata). Study design Prospective experimental trial. Animals A total of 16 apparently clinically healthy adult ornate box turtles (eight male, eight female). Methods Each turtle was treated with dexmedetomidine (0.1 mg kg(-1)), midazolam (1 mg kg(-1)) and ketamine (10 mg kg(-1)) administered IM. Time to first response, time to maximal effect, the plateau phase and time to recovery from reversal administration were recorded. Physiologic variables, muscle tone, reflexes and the ability to perform endotracheal intubation were recorded at 5 minute intervals. Movement in response to an IM injection of 0.1 mL sterile 0.9% NaCl administered in the left pelvic limb, using a 25 gauge needle to a depth of just past the bevel of the needle, was assessed every 15 minutes. Atipamezole (0.5 mg kg(-1)) IM and flumazenil (0.05 mg kg(-1)) SC were administered 60 minutes after the initial DMK injections. Results The mean time to first response, time to maximal effect, the plateau phase and time to recovery were 2.1, 14.9, 38.7 and 7.8 minutes, respectively. A respiratory rate was not observed in most turtles. The body temperature significantly increased over time. The palpebral reflex was persistent in 43% of turtles and the tail pinch reflex remained intact in 13% of turtles. All turtles recovered with no observed adverse effects. Conclusions and clinical relevance In this study, this DMK protocol administered to ornate box turtles resulted in a rapid-onset, light anesthesia lasting approximately 40 minutes and a smooth recovery with no adverse effects noted.