Pulmonary gas exchange and acid–base status during immobilisation of black rhinoceroses (Diceros bicornis) in Zimbabwe

Authors

  • Åsa Fahlman Swedish University of Agricultural Sciences
  • Anna Edner Swedish University of Agricultural Sciences
  • Sandra Wenger University of Zürich
  • Chris Foggin Victoria Falls Wildlife Trust
  • Görel Nyman Swedish University of Agricultural Sciences

Abstract

When immobilising wildlife, adverse side effects can include hypoxaemia, acidosis and hypertension. Pulmonary gas exchange and acid–base status were evaluated during immobilisation of 25 free-ranging and one boma-held black rhinoceros (Diceros bicornis) in Zimbabwe. The effect of different body positions on arterial oxygenation was evaluated. A combination of the following drugs was used: an opioid (etorphine or thiafentanil), azaperone and an a2 -adrenoceptor agonist (detomidine or xylazine). Respiratory and heart rates, rectal temperature and pulse oximetry–derived haemoglobin oxygen saturation were recorded. Serial arterial blood samples were analysed immediately in the field. Marked hypoxaemia and hypercapnia were  recorded in immobilised free-ranging black rhinoceroses. Arterial oxygenation was higher during sternal compared to lateral recumbency. Most rhinoceroses developed acidaemia of respiratory and metabolic origin. Initially high lactate concentrations
in free-ranging rhinoceroses decreased during immobilisation. Pulse oximetry was unreliable in the detection of hypoxaemia. Positioning in sternal recumbency and routine use of oxygen supplementation are recommended in the management of immobilised rhinoceroses as measures to improve arterial oxygenation.

Author Biographies

  • Åsa Fahlman, Swedish University of Agricultural Sciences

    Department of Clinical Sciences, Swedish University of Agricultural Sciences, Sweden

  • Anna Edner, Swedish University of Agricultural Sciences

    Department of Clinical Sciences, Swedish University of Agricultural Sciences, Sweden

  • Sandra Wenger, University of Zürich

    Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zürich, Switzerland

  • Chris Foggin, Victoria Falls Wildlife Trust

    Victoria Falls Wildlife Trust, Victoria Falls, Zimbabwe

  • Görel Nyman, Swedish University of Agricultural Sciences

    Department of Clinical Sciences, Swedish University of Agricultural Sciences, Sweden

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Published

2021-12-09

Issue

Section

Original Research