Sedative Effects of Intranasal Midazolam and Dexmedetomidine in 2 Species of Tortoises (Chelonoidis carbonaria and Geochelone platynota)

The sedative effects of intranasal midazolam and dexmedetomidine were evaluated in 2 tortoise species as a means to facilitate handling and performing diagnostic procedures. Six red-footed tortoises ( Chelonoidis carbonaria ) and 6 Indian star tortoises ( Geochelone platynota ) received the following treatments in a randomized order with 2-week washout periods between the treatments: midazolam (0.5 and 1.5mg/kg), dexmedetomidine (0.05 and 0.15mg/kg), and saline control. Tortoises were evaluated and scored for sedation (using a previously published subjective method) by blinded observers, and results were averaged for each species and treatment group. Low-dose dexmedetomidine (0.05mg/kg) in red-footed tortoises resulted in a significantly higher median sedation score at 5 minutes compared with other treatments. Control saline resulted in a higher median sedation score 5 minutes after administration in Indian star tortoises compared with red-footed tortoises. No other significant differences were observed between treatments or between species. The results suggest that intranasal administration of midazolam or dexmedetomidine, at the dosages used in this study, do not provide effective sedation in red-footed tortoises or Indian star tortoises, based on a subjective scoring system.