A fast and simple protocol to anaesthesia in chicken embryos

Abstract Our goal was to evaluate different anaesthetic protocols in CEs using an easy inoculation route via a shell membrane (SM). For this, we adopted the heart rate by pulse and movement of the CE as a parameter of pain by assessing the vase in the chorioallantoic membrane (CAM) directly in the shell. CEs were distributed into the following groups: association of ketamine (5 mg/CE), midazolam (0.05 mg/CE), and morphine (0.15 mg/CE); ketamine (5 mg/CE) and xylazine (0.125 mg/CE); xylazine (0.0125 mg/CE) and morphine (0.15 mg/CE). In this experimental model, associations between different drugs decreased the pulse and the movement, indicating possible sedation. The best result was the association of ketamine (5 mg/CE), midazolam (0.05 mg/CE), and xylazine (0.125 mg/CE) or the association of ketamine (5 mg/CE) and xylazine (0.125 mg/CE). Therefore, we recommend these associations for use in embryos in the final third of embryonic development in experimental protocols and euthanasia.