Comparison of some cardiopulmonary effects of etorphine and thiafentanil during the chemical immobilization of blesbok (Damaliscus pygargus phillipsi)

A comparison of immobilisation quality and cardiorespiratory effects of etorphine-azaperone versus etorphine-midazolam combinations in blesbok

“…Significant differences were, however, found in the quality of immobilisation as well as the physiological response of the blesbok to these drug combinations. The time to recumbency did not differ between the combinations (T1 = 3.2 ± 0.7 minutes; T2 = 3.5 ± 2.2 minutes) and was similar to results reported by Pfitzer et al (2019) when 0.09 mg/kg etorphine was used as the sole drug to immobilise blesbok. It therefore appears that the addition of azaperone or midazolam to etorphine did not influence the time to recumbency.…”

Arterial oxygenation and acid–base status before and during oxygen supplementation in captive European bison (Bison bonasus) immobilized with etorphine-acepromazine-xylazine

“…Both etorphine and xylazine are respiratory depressants ( 33 ), and have been associated with hypoxemia during immobilization of ruminants ( 35–40 ). Etorphine is reported to decrease the responsiveness of central chemoreceptors to the variation in P a CO 2 ( 29 ) inducing a dose-dependent respiratory depression in ruminants resulting in hypoventilation ( 28 , 31 ). A similar effect of xylazine on central responsiveness to CO 2 is reported ( 29 ).…”

“…Acepromazine, a phenothiazine, is combined with etorphine for its anxiolytic effects in Large Animal Immobilon® ( 29 ). Xylazine is an alpha-2 adrenoceptor agonist producing a dose-dependent sedation, analgesia and muscle relaxation ( 30 , 31 ). The combination of these drugs potentiates their effect allowing reduced volume and mitigating some side effects of etorphine such as excitement or muscle rigidity ( 28 , 29 ).…”

“…Hypoxemia, and consequent hypoxia, associated with hypoventilation, and secondary acid–base disturbances are also common complications of ruminant immobilization using this combination ( 13 ). Both etorphine ( 28 , 31 ) and xylazine ( 30 , 32 , 34 ) affect blood oxygenation and their combination, with or without acepromazine, has been reported to induce hypoxemia and metabolic disorders in moose ( Alces alces ) ( 35 , 36 ), muskox ( Ovibos moschatus ) ( 37 ), reindeer ( Rangifer tarandus ) ( 38 ), rhebok ( Pelea capreolus ) ( 39 ), and scimitar horned oryx ( Oryx dammah ) ( 40 ). Prolonged hypoxemia and metabolic disorders can lead to some level of organ dysfunction, such as postanesthetic renal or cardiac insufficiency ( 41 ), and can affect recovery ( 13 , 38 ).…”

Evaluation of two different etorphine doses combined with azaperone in blesbok (Damaliscus pygargus phillipsi) immobilisation

“…Butyrophenones are also believed to be beneficial in wildlife immobilisation because of their mild antagonistic activity on α 1 -adrenergic receptors, leading to peripheral vasodilation that can be used to counter hypertension (Riviere & Papich 2009). Despite their extensive use, very few immobilising drug combinations have been scientifically assessed for quality of immobilisation and physiological effects in different antelope species; in particular, very little work has been carried out on blesbok (Du Plessis 2018;Semjonov et al 2018;Pfitzer et al 2019Pfitzer et al , 2021Zeiler & Meyer 2017). Recently, the authors of this article compared the quality of immobilisation and cardiorespiratory effects of a high dose of etorphine alone (0.09 mg kg -1 ) and an etorphine (0.09 mg kg -1 ) azaperone (0.35 mg kg -1 ) combination in blesbok (Gaudio et al 2020b).…”