Immobilisation efficacy of conducted electrical weapons on captive white-tailed deer

Abstract

Context Wildlife emergencies (e.g. injured animals) often require capture or humane dispatch of animals to resolve the situation. Conducted electrical weapons (CEWs) have the potential to immobilise white-tailed deer (Odocoileus virginianus) for a short duration to avoid potential risks of extended immobilisation (e.g. chemical immobilisation) and increase safety for managers and the public during humane killing by gunshot. Aims To test rapid immobilisation with minimal long-term physiological consequences of CEW immobilisation of white-tailed deer. Methods We arranged five treatment groups of captive deer, including (1) chemical immobilisation with 5-s CEW exposure (n = 5), (2) chemical immobilisation with 15-s CEW exposure (n = 5), (3) 5-s CEW exposure with no chemical immobilisation (n = 10), (4) 15-s CEW exposure with no chemical immobilisation (n = 10) and (5) a control group with no chemical immobilisation or CEW exposure (n = 10). We conducted treatments 1 and 2 to determine short-term physiological effects of CEWs on deer, related to overall welfare. In treatment groups 1 and 2, we sedated deer to collect blood immediately before CEW exposure, and 2 days and 5 days post-exposure for serum biochemical analysis (to measure physiological markers of organ and tissue damage). We observed deer before, during and after treatments to evaluate potential behavioural changes. Key results All deer showed signs of muscle paralysis immediately after exposure to CEW and regained muscle control immediately after the exposure ended. Serum biochemistry results for treatment group 1 and 2 revealed significant increases in creatine kinase (CK) and aspartate aminotransferase (AST) 2 days post-treatment, before returning to pre-exposure concentrations by day 5-post-exposure, suggesting temporary myopathy. By 15-days post-exposure, deer that were only exposed to the CEW had 27 of 39 (69%) remotely fired probes still attached. No long-term behavioural or physiological changes were observed post-treatment. Conclusions Our findings suggest that for immobilisation of white-tailed deer, short-term exposure to a CEW to is a potential alternative to typical capture techniques and can provide sufficient immobilisation to approach and humanely kill deer by gunshot if necessary in wildlife emergencies. Implications As with all capture techniques, trainings and protocols should be developed to ensure the safety of personnel and animals during CEW exposures.