Comparison of xylazine–ketamine and medetomidine–ketamine anaesthesia in the Iberian ibex (Capra pyrenaica)

Abstract

A comparison was made between two anaesthetic combinations in 35 free-ranging adult Iberian ibexes (Capra pyrenaica), from May to December 2005. Sixteen ibexes (10 males, 6 females) were captured using xylazine–ketamine (3.0 ± 0.4 + 3.0 ± 0.4 mg/kg) and 19 ibexes (12 males, 7 females) with medetomidine–ketamine (0.10 ± 0.02 + 2.1 ± 0.3 mg/kg). Anaesthetic times were evaluated, as well as clinical variables (respiratory and heart rates, rectal temperature, haemoglobin oxygen saturation), haematological and biochemical variables, at the time of induction and after 1 h. The heart rate of ibex immobilized with medetomidine–ketamine was higher than those immobilized with xylazine–ketamine. Stabilization of the heart rate of ibex immobilized with medetomidine–ketamine came earlier than those immobilized with xylazine–ketamine. Rectal temperature decreased and stabilized in both groups, but earlier in the xylazine–ketamine group, and hypoxemia was observed in both groups. The white blood cell count of ibex immobilized with medetomidine–ketamine was lower than those immobilized with xylazine–ketamine throughout anaesthesia, while sodium concentration was higher only after 1 h of anaesthesia. In ibex immobilized with xylazine–ketamine, the neutrophil count, serum creatinine kinase activity and aspartate aminotransferase activity increased after 1 h of immobilization, while triglycerides decreased. Changes found in haematological and biochemical variables suggest no major differences in the different drug combinations used, but clinical findings of this study, as well as hypoxemia, hypothermia and bradycardia, were important records that should be taken into account when performing a safe operation.