Afema Josephine A, Beckmen Kimberlee B, Arthur Stephen M, Huntington Kathy Burek, Mazet Jonna A K
1 Wildlife Health Center, One Health Institute, School of Veterinary Medicine, University of California, 1089 Veterinary Medicine Drive, Davis, California 95616, USA.
2 Alaska Department of Fish and Game, Division of Wildlife Conservation, 1300 College Road, Fairbanks, Alaska 99701, USA.
J Wildl Dis. 2017 Apr;53(2):311-329. doi: 10.7589/2016-02-035. Epub 2017 Jan 18.
The muskox ( Ovibos moschatus ) population inhabiting the eastern North Slope (ENS) of Alaska, US declined dramatically during 1999-2006, whereas populations in western Alaska (WA) were stable or increasing. To understand morbidity and mortality factors contributing to the decline, Alaska Department of Fish and Game conducted pathologic investigations of carcasses from 2005 until 2008. Additionally, archived sera from both ENS and WA muskoxen collected during 1984-92, before the documented beginning of the ENS decline; sera collected during 2000, near the beginning of the decline; and contemporary sera (from live capture-release, adult females) collected during 2006, 2007, and 2008 were analyzed to determine whether prevalence of antibody to potential pathogens differed in the two areas or changed over time. The pathogens investigated were those that were believed could cause lameness or poor reproduction or adversely affect general health. Furthermore, trace mineral levels, hemograms, and gastrointestinal parasites were evaluated in live adult females captured 2006-08. Pathologic investigations identified several comorbid conditions, including predation, polyarthritis caused by or consistent with Chlamydophila spp. infection, hoof lesions, copper deficiency, contagious ecthyma, verminous pneumonia, hepatic lipidosis suggestive of negative energy balance, and bacterial bronchopneumonia due to Trueperella pyogenes and Bibersteinia trehalosi . Pathogens suspected to be newly introduced in the ENS muskox population on the basis of serologic detection include bovine viral diarrhea, respiratory syncytial virus, Chlamydophila spp., Brucella spp., Coxiella burnetii , and Leptospira spp., whereas parainfluenza virus-3 antibody prevalence has increased in the WA population. Although multiple disease syndromes were identified that contributed to mortality and, in combination, likely limited the ENS muskox population, further holistic investigations of disease agents, trace mineral status, and nutritional factors in conjunction with intensive demographic and environmental analyses would provide a better understanding of factors that influence Alaskan muskox populations.
栖息在美国阿拉斯加北坡东部（ENS）的麝牛（Ovibos moschatus）种群数量在1999年至2006年期间急剧下降，而阿拉斯加西部（WA）的种群数量则保持稳定或有所增加。为了解导致种群数量下降的发病和死亡因素，阿拉斯加鱼类和野生动物管理部门在2005年至2008年期间对尸体进行了病理学调查。此外，还分析了1984年至1992年期间（ENS种群数量下降记录开始之前）从ENS和WA麝牛采集的存档血清；2000年（种群数量下降开始时）采集的血清；以及2期006年、2007年和2008年采集的当代血清（来自成年雌性活体捕获-放归），以确定这两个地区针对潜在病原体的抗体流行率是否存在差异或随时间变化。所调查的病原体是那些被认为可能导致跛行、繁殖能力下降或对总体健康产生不利影响地病原体。此外，还对2006年至2008年捕获的成年雌性活体地微量矿物质水平、血常规和胃肠道寄生虫进行了评估。病理学调查确定了几种合并病症，包括捕食、由嗜衣原体属感染引起或与之相符的多关节炎、蹄部病变、铜缺乏、传染性脓疱病、蠕虫性肺炎、提示负能量平衡的肝脂肪变性以及由化脓隐秘杆菌和溶血贝氏杆菌引起的细菌性支气管肺炎。根据血清学检测怀疑在ENS麝牛种群中 newly introduced的病原体包括牛病毒性腹泻、呼吸道合胞病毒、嗜衣原体属、布鲁氏菌属、伯氏考克斯氏体和钩端螺旋体属，而3型副流感病毒抗体流行率在WA种群中有所增加。尽管已确定多种疾病综合征导致了死亡，并且综合起来可能限制了ENS麝牛种群数量，但进一步全面调查疾病病原体、微量矿物质状况和营养因素，并结合深入的人口统计学和环境分析，将有助于更好地了解影响阿拉斯加麝牛种群的因素。
