Comparison of three reversible injectable chemical restraint protocols in Spix´s Owl monkeys (Aotus vociferans) using ketamine, xylazine and midazolam.

BACKGROUND

There is scarce information detailing clinical and physiological effects of reversible injectable protocols of chemical restraint on Neotropical primates.

METHODS

Nineteen captive Spix´s Owl monkeys (Aotus vociferans) were assessed in a double-blind randomized crossover study using the following: ketamine/xylazine [KX], ketamine/midazolam [KM] and ketamine/xylazine/midazolam [KXM]. During immobilization, respiratory and pulse rates, rectal temperature, haemoglobin oxygen saturation and arterial blood pressure were recorded at 5-minute intervals during a 20-minute period; afterwards, antagonist drugs (yohimbine for xylazine and flumazenil for midazolam) were, respectively, administered. Quality and duration of induction, immobilization and recovery periods were recorded.

RESULTS

Ketamine/xylazine increased manipulation sensitivity and produced poor muscle relaxation. KM maintained all assessed parameters within physiological ranges. KXM produced depressant cardiorespiratory effects and hypotension. All protocols produced hypothermia.

CONCLUSIONS

Based on its adequate anaesthetic depth and minimum effects on physiological parameters, KM is suitable for immobilizing A vociferans and performing short-term procedures lasting around 20 minutes.