Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, USA.
Department of Small Animal Clinical Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, USA.
Vet Pathol. 2020 Mar;57(2):311-315. doi: 10.1177/0300985819900017. Epub 2020 Feb 21.
An outbreak of canine distemper virus in a private zoo in eastern Tennessee in July 2016 led to fatal clinical disease in 5 adult, wild-caught Linnaeus's 2-toed sloths (). Clinical signs included hyporexia, lethargy, mucopurulent nasal discharge, and oral and facial ulcers. At necropsy, affected animals had crusts and ulcers on the lips, nose, tongue, and oral cavity. Microscopically, all sloths had widespread, random, hepatic necrosis; lymphoid depletion; and bronchointerstitial pneumonia. The central nervous system did not contain gross or histopathologic lesions in any of the 5 sloths, although immunoreactivity for viral antigen was present within vessel walls. Epithelial cells and histiocytes within numerous organs contained intranuclear and intracytoplasmic inclusions and occasional syncytial cells. Canine distemper virus was confirmed with immunohistochemistry and virus isolation. Viral sequencing identified the novel American-4 strain prevalent in eastern Tennessee wildlife. This is the first pathologic characterization of canine distemper virus infection in sloths (family Choloepodidae, order Pilosa) and emphasizes the significant morbidity and mortality in this species.
2016 年 7 月，田纳西州东部一家私人动物园爆发犬瘟热病毒，导致 5 只成年野生林奈两趾树懒（）出现致命临床疾病。临床症状包括食欲减退、嗜睡、黏液脓性鼻分泌物和口腔及面部溃疡。剖检时，患病动物唇部、鼻部、舌头和口腔有结痂和溃疡。组织病理学检查显示，所有树懒均有广泛、随机的肝坏死；淋巴细胞耗竭；以及支气管间质性肺炎。5 只树懒的中枢神经系统均未出现肉眼或组织病理学病变，但血管壁内存在病毒抗原免疫反应。许多器官的上皮细胞和组织细胞内存在核内和胞浆内包涵体，偶尔有合胞体细胞。通过免疫组织化学和病毒分离法确认了犬瘟热病毒。病毒测序鉴定出在美国田纳西州野生动物中流行的新型美国-4 株。这是首例对树懒（树懒科，披毛目）犬瘟热病毒感染的病理特征描述，强调了该物种的高发病率和死亡率。
