Association of S(+) ketamine, dexmedetomidine and butorphanol for chemical restraint in scarlet macaws (Ara macao)

Abstract

The present study aimed at assessing the effects of combining 20 mg/kg S(+) ketamine with 25 μg/kg dexmedetomidine and 0.4 mg/kg butorphanol on the physiological parameters and anesthetic recovery time and score of eight captive scarlet macaw (Ara macao) specimens. These specimens were captured at the Marabá Zoobotanic Foundation (Fundação Zoobotânica de Marabá), Pará, using butterfly and mist nets, and subsequently subjected to the proposed protocol. The following physiological parameters were evaluated: heart rate (HR), respiratory rate (RR), saturation of peripheral oxygen (SpO2), body temperature (BT), and non-invasive blood pressure 5 min after drug administration (M0) and every 10 min thereafter (M1‒M5), with a total of 55 min of analysis of anesthetic effects. Glycemia was measured 5 min after drug administration and every 30 min thereafter. Anesthetic induction and recovery times were also determined. Among the parameters evaluated in this study, both HR and BT significantly decreased throughout the anesthetic period, with the lowest levels at 55 min after drug administration (M5). In contrast, RR did not significantly differ, and all animals remained stable, maintaining an RR close to a mean of 20 ± 8 cpm. Throughout the anesthetic period, SpO2 was 92 ± 5%, with no significant difference. The birds remained under spontaneous ventilation and without oxygen supplementation. Systolic, diastolic, and mean blood pressures remained stable, with no significant differences in any of these measurements. At M0 and M3, the glycemia decreased slightly, albeit with no significant difference justifying an adverse effect or even hypoglycemia. The anesthetic induction time, from M0 to decubitus, was 2.4 ± 0.7 min. The anesthetic recovery time, from M0 to effortless bipedal position and adequate phalangeal flexion, was 99.3 ± 32.4 min. The sedation was assessed as intense, and the anesthetic recovery was rated excellent in 62.5% and good in 37.5% of the animals.