Department of Pathobiology, University of Guelph, 50 Stone Road E, Guelph, Ontario N1G 2W1, Canada.
Department of Population Medicine, University of Guelph, 50 Stone Road E, Guelph, Ontario N1G 2W1, Canada.
J Wildl Dis. 2020 Oct 1;56(4):884-895. doi: 10.7589/JWD-D-19-00018.
Free-ranging cervids in Canada face diverse threats such as climate change, human population expansion, and the northward spread of vector-borne pathogens. However, we currently have a limited understanding of the impacts of these health challenges in Ontario cervids. Our objective was to identify and characterize causes of morbidity and mortality in free-ranging cervids submitted to the Ontario and Nunavut node of the Canadian Wildlife Health Cooperative (CWHC) over a 27-yr period (1991 to 2017). Submissions included carcasses submitted for full postmortem examination (gross and histopathology; n=196) and field-collected tissues (n=384). Ancillary tests were performed on a case-by-case basis. Univariable logistic regression was used to test for associations between select causes of morbidity and mortality, and factors such as sex, age, and season. Four cervid species were examined: white-tailed deer (Odocoileus virginianus; n=211), moose (Alces alces; n=140), elk (Cervus canadensis; n=136), and caribou (Rangifer tarandus caribou; n=93). Noninfectious disease was the most common general cause of morbidity and mortality (38.1%; 221/580) and was most commonly attributed to trauma (49.7%; 110/221). Deaths attributed to infectious diseases (34.3%; 199/580) were most often bacterial in etiology (45.7%; 91/199). The most common primary infectious disease diagnosed in caribou was digital limb infection, and moose were most commonly diagnosed with parasitic causes, including meningeal worm (Parelaphostrongylus tenuis) and winter tick (Dermacentor albipictus). Chronic wasting disease was not diagnosed among cervids tested during the study period, consistent with the previous lack of detection of the disease in Ontario. These results reveal that anthropogenic, infectious, and environmentally associated causes of morbidity and mortality are commonly diagnosed in cervids submitted to the CWHC Ontario and Nunavut regions, and represent potential population threats that should continue to be monitored.
加拿大的自由放养的有蹄类动物面临着多种威胁，如气候变化、人类人口扩张以及传播媒介传播的病原体向北传播。然而，我们目前对安大略省有蹄类动物所面临的这些健康挑战的影响了解有限。我们的目标是确定并描述在加拿大野生动物健康合作组织（CWHC）安大略省和努纳武特节点提交的 27 年期间（1991 年至 2017 年）自由放养的有蹄类动物的发病和死亡原因。提交的材料包括提交进行全面尸检（大体病理和组织病理学；n=196）和现场采集的组织（n=384）。根据具体情况进行辅助检测。单变量逻辑回归用于测试发病和死亡的选择原因与性别、年龄和季节等因素之间的关联。检查了四种有蹄类动物：白尾鹿（Odocoileus virginianus；n=211）、驼鹿（Alces alces；n=140）、麋鹿（Cervus canadensis；n=136）和北美驯鹿（Rangifer tarandus caribou；n=93）。非传染性疾病是发病和死亡的最常见一般原因（38.1%；221/580），最常见的原因是创伤（49.7%；110/221）。归因于传染病的死亡（34.3%；199/580）在病因学上最常由细菌引起（45.7%；91/199）。在北美驯鹿中诊断出的最常见的原发性传染病是指部感染，而驼鹿最常见的诊断原因是寄生虫病，包括脑膜蠕虫（Parelaphostrongylus tenuis）和冬季蜱（Dermacentor albipictus）。在研究期间未检测到慢性消耗病，这与安大略省以前未检测到该疾病的情况一致。这些结果表明，在提交给 CWHC 安大略省和努纳武特地区的有蹄类动物中，常见的发病和死亡原因是人为的、传染性的和与环境相关的，这是应该继续监测的潜在种群威胁。
