Comparison of subcutaneous dexmedetomidine-midazolam versus alfaxalone-midazolam sedation in leopard geckos (Eublepharis macularius).

OBJECTIVE: To compare dexmedetomidine-midazolam with alfaxalone-midazolam for sedation in leopard geckos (Eublepharis macularius).

STUDY DESIGN: Prospective, randomized, blinded, complete crossover study.

ANIMALS: Nine healthy adult leopard geckos.

METHODS: Geckos were administered a combination of dexmedetomidine (0.1 mg kg-1 ) and midazolam (1.0 mg kg-1 ; treatment D-M) or alfaxalone (15 mg kg-1 ) and midazolam (1.0 mg kg-1 ; treatment A-M) subcutaneously craniodorsal to a thoracic limb. Heart rate (HR), respiratory rate (fR ), righting reflex, palpebral reflex, superficial and deep pain reflexes, jaw tone and escape response were assessed every 5 minutes until reversal. Conditions for intubation and response to needle prick were evaluated. Antagonist drugs [flumazenil (0.05 mg kg-1 ) ± atipamezole (1.0 mg kg-1 )] were administered subcutaneously, craniodorsal to the contralateral thoracic limb, 45 minutes after initial injection, and animals were monitored until recovery.

RESULTS: HR, but not fR , decreased significantly over time in both treatments. HR was significantly lower than baseline at all time points in D-M and for all but the 5 and 10 minute time points in A-M. HR was significantly higher in A-M at all time points after drug administration when compared with D-M. Sedation scores between protocols were similar for most time points. All animals in A-M lost righting reflex compared with seven out of nine (78%) geckos in D-M. Geckos in A-M lost righting reflex for significantly longer time. Mean ± standard deviation time to recovery after antagonist administration was 6.1 ± 2.2 minutes for D-M and 56 ± 29 minutes for A-M, and these times were significantly different.

CONCLUSIONS AND CLINICAL RELEVANCE: Combination D-M or A-M provided sedation of a level expected to allow physical examinations and venipuncture in leopard geckos. A-M provided a faster onset of sedation compared with D-M. Recovery was significantly faster following antagonist reversal of D-M, compared with A-M.