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Background: The provincial wildlife management agency, British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development, performed a translocation to control the urban mule deer ( Odocoileus hemionus ; uMD) overpopulation and supplement the declining non-urban mule deer (nuMD) population in the Kootenay region, British Columbia, Canada. The objectives of this cross-sectional study were to evaluate the health of the urban and nuMD populations by comparing pathogen exposure, body condition scores (BCS) and pregnancy rates, to characterize the health risks associated with the translocation and to investigate the role of infectious diseases in the decline of the nuMD deer population., Methods: Two hundred free-ranging mule deer were captured in urban and non-urban environments in the Kootenay region from 2014 to 2017. BCS and morphometric examinations were performed for each deer. Blood samples collected from each deer were tested for exposure to selected pathogens and pregnancy status., Results: Body condition scores averaged 3.4 on a five-point scale, was greater in nuMD, and significantly differed between years. Antibodies were detected for adenovirus hemorrhagic disease virus (38.4% (uMD 43.7%, nuMD 33.3%)), bluetongue virus (0.6% (uMD 1.2%, nuMD 0%)), bovine respiratory syncytial virus (8.4% (uMD 4.6%, nuMD 12.1%)), bovine viral diarrhea virus (1.1% (uMD 0%, nuMD 2.2%)), bovine parainfluenza-3 virus (27.0% (uMD 27.6%, nuMD 26.4%)), Neospora caninum (22.1% (uMD 24.4%, nuMD 19.7%)) and Toxoplasma gondii (8.2% (uMD 12.3%, nuMD 3.9%)). No antibodies against epizootic hemorrhagic disease virus were detected. Pregnancy rates did not differ between the two deer populations (90.7% (uMD 90.6%, nuMD 90.9%)). Exposure to N. caninum was associated with a reduced probability of being pregnant. uMD were more likely to be exposed to T. gondii than nuMD., Discussion: Comparison of BCS, pregnancy rates and pathogen exposure of uMD and nuMD showed that the health of the two populations did not significantly differ, suggesting uMD translocations do not pose a severe risk of pathogen transmission between mule deer populations and that these selected pathogens do not factor in the decline of the nuMD population. However, inclusion of additional health indicators and creation of a robust predictive disease model are warranted to further characterize the health of mule deer and the health risks associated with uMD translocations. These results should be considered as part of a formal risk assessment for future uMD translocations in southeastern British Columbia., Competing Interests: The authors declare that they have no competing interests.

The combination of medetomidine, azaperone, and alfaxalone has been successfully used to anesthetize captive white-tailed deer ( Odocoileus virginianus ). This same combination was utilized to immobilize free-ranging female mule deer ( Odocoileus hemionus ; MD) in urban and nonurban environments (14 urban MD, 14 nonurban MD) in British Columbia, Canada. Physiologic data were collected to assess the safety and reliability of this drug combination under field conditions. Each deer received estimated dosages of 0.15 mg/kg medetomidine, 0.2 mg/kg azaperone, and 0.5 mg/kg alfaxalone intramuscularly via a remote darting system. Inductions were calm and rapid (mean time to sternal recumbency: urban MD, 6.4±2.2 min; nonurban MD, 8.2±4.1 min). Supplemental drugs were required to induce lateral recumbency in five deer, four of which had experienced initial dart failure (mean time to lateral recumbency: urban MD, 8.5±3.8 min; nonurban MD, 18.7±16.5 min). Recoveries were smooth and uneventful (time to standing: urban MD, 12.5±3.4 min; nonurban MD, 9.0±3.5 min) for all but one debilitated nonurban MD that died shortly after atipamezole administration (at five times the medetomidine dose). The major side effects of the combination were hypoxemia and hypercapnia. The combination of medetomidine, azaperone, and alfaxalone proved suitable for the immobilization of urban and nonurban free-ranging MD.