Feasibility of “test-and-cull” for managing chronic wasting disease in urban mule deer

Abstract Strategies for managing chronic wasting disease (CWD) in urban mule deer (Odocoileus hemionus) populations are needed in Colorado. We captured, tonsil-biopsied, marked, and tested adult mule deer (n=181) to evaluate the feasibility of conducting an urban “test-and-cull” program in Estes Park, Colorado. During December 2002 and April–May 2003, we successfully tested 51 (57%) of the estimated 89 male and 130 (50%) of the estimated 261 female mule deer wintering in Estes Park for evidence of CWD. Nine (18%) males and 6 (5%) females tested positive for CWD infection via immunohistochemistry. All 15 test-positive deer were removed from the population; we culled 13 of these, and 2 died of other causes before being culled. We completed all sampling and inventory work in 34 field days and culled all test-positive deer in another 7 field days. Personnel time associated with sampling, culling, and inventory averaged 5.2 person-hours/deer. Average drug costs varied by combination (tiletamine–zolazepam–xylazine: $22; thiafentanil–xylazine: $66). Additional fixed costs averaged $215/deer for telemetry devices and $60/deer for vehicle and other testing-related expenses. Based on our initial assessment, sampling ≥50% of the mule deer in Estes Park annually is feasible.