Effect of Azaperone on Blood Pressure and Other Cardiorespiratory Parameters in Etorphine-Immobilized Free-Ranging African Elephants—Role in Managing Anesthetic Complications
American Association of Zoo Veterinarians Conference 2014
Peter Buss1, BVSc, MMedVet; Michele Miller2, DVM, MPH, PhD; Jennifer Hofmeyr1, BTech (Vet), BSc(Hon); Guy Hausler1, BSc (Mech Eng); Rachel Wanty3, BS; Francisco Olea-Popelka3,4, DVM, MS, PhD
1Veterinary Wildlife Services, South African National Parks, Kruger National Park, Skukuza, South Africa; 2DST/NRF Centre of Excellence for Biomedical TB Research/MRC Centre for Molecular and Cellular/Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa; 3Applied Veterinary Epidemiology (AVE) Research Group, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA; 4Department of Clinical Sciences and Mycobacteria Research Laboratories, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
Etorphine is commonly used to immobilize elephants. However potential adverse cardiovascular effects include hypertension.1 This has been associated with development of pulmonary edema and death. Addition of azaperone to the immobilizing combination may provide synergistic effects and counteract cardiovascular effects of etorphine. This study was undertaken to assess the cardiorespiratory effects of azaperone either added to the initial drug combination or administered IV after immobilization of free-ranging African elephants.
Fifty-five bull African elephants were immobilized with either etorphine alone or etorphine with azaperone in the dart, or etorphine with azaperone administered IV 10 minutes after recumbency. Cardiorespiratory parameters were monitored every 5 minutes, including invasive blood pressure values using an auricular artery. Although median heart rates were not different before and after IV azaperone (50 and 51 bpm, respectively), values for systolic (229 vs. 156 mm Hg), diastolic (158 vs. 117.5 mm Hg), mean blood pressures (187 vs. 132 mm Hg) and pulse pressures (76 vs. 45 mm Hg) were significantly lower after administration of IV azaperone (p<0.0001). Similarly, when parameters for elephants administered etorphine alone with etorphine and azaperone in the dart were compared, elephants receiving azaperone had significantly lower blood pressure values. This study supports the use of azaperone to minimize cardiovascular complications associated with etorphine immobilization in elephants, although caution should be used when administering azaperone IV.
The authors thank the South African National Parks for funding this project. The authors acknowledge the essential role of the veterinary teams, capture teams, and helicopter pilots of South African National Parks in safely immobilizing the elephants used for this study.
1. Kock MD, Burroughs R, eds. 2012. Chemical and Physical Restraint of Wild Animals. Greyton, South Africa: International Wildlife Veterinary Service (Africa); 2012.