Rothenburger Jamie L, Himsworth Chelsea G, La Perle Krista M D, Leighton Frederick A, Nemeth Nicole M, Treuting Piper M, Jardine Claire M
Department of Pathobiology, Ontario Veterinary College, University of Guelph and Canadian Wildlife Health Cooperative (CWHC; Ontario-Nunavut Region), Guelph, ON, Canada (Rothenburger, Nemeth, Jardine).
Animal Health Centre, British Columbia Ministry of Agriculture and CWHC (British Columbia Region), Abbotsford, BC, Canada (Himsworth).
J Vet Diagn Invest. 2019 Mar;31(2):184-199. doi: 10.1177/1040638719833436.
To achieve a contemporary understanding of the common and rare lesions that affect wild, urban Norway rats ( Rattus norvegicus), we conducted a detailed pathology analysis of 672 rats from Vancouver, British Columbia, Canada. Grossly evident lesions, such as wounds, abscesses, and neoplasms, were present in 71 of 672 rats (11%) and tended to be severe. The most common and significant lesions were infectious and inflammatory, most often affecting the respiratory tract and associated with bite wounds. We assessed a subset of rats (up to n = 406 per tissue) for the presence of microscopic lesions in a variety of organ systems. The most frequent lesions that could impact individual rat health included cardiomyopathy (128 of 406; 32%), chronic respiratory tract infections as indicated by pulmonary inducible bronchus-associated lymphoid tissue (270 of 403; 67%), tracheitis (192 of 372; 52%), and thyroid follicular hyperplasia (142 of 279; 51%). We isolated 21 bacterial species from purulent lesions in rats with bacterial infections, the most frequent of which were Escherichia coli, Enterococcus sp., and Staphylococcus aureus. Parasitic diseases in rats resulted from infection with several invasive nematodes: Capillaria hepatica in the liver (242 of 672; 36%), Eucoleus sp. in the upper gastrointestinal tract (164 of 399; 41%), and Trichosomoides crassicauda in the urinary bladder (59 of 194; 30%). Neoplastic, congenital, and degenerative lesions were rare, which likely reflects their adverse effect on survival in the urban environment. Our results establish a baseline of expected lesions in wild urban rats, which may have implications for urban rat and zoonotic pathogen ecology, as well as rat control in cities worldwide.
为了对影响野生和城市挪威大鼠（褐家鼠）的常见和罕见病变有一个当代的认识，我们对来自加拿大不列颠哥伦比亚省温哥华的672只大鼠进行了详细的病理学分析。在672只大鼠中有71只（11%）存在明显的肉眼可见病变，如伤口、脓肿和肿瘤，且往往较为严重。最常见且重要的病变是感染性和炎症性病变，最常累及呼吸道并与咬伤有关。我们评估了一部分大鼠（每个组织最多n = 406只）在各种器官系统中是否存在微观病变。可能影响个体大鼠健康的最常见病变包括心肌病（406只中有128只；32%）、肺部诱导性支气管相关淋巴组织所提示的慢性呼吸道感染（403只中有270只；67%）、气管炎（372只中有192只；52%）以及甲状腺滤泡增生（279只中有142只；51%）。我们从患有细菌感染的大鼠的脓性病变中分离出21种细菌，其中最常见的是大肠杆菌、肠球菌属和金黄色葡萄球菌。大鼠的寄生虫病是由几种侵袭性线虫感染引起的：肝脏中的肝毛细线虫（672只中有242只；36%）、上消化道中的真杆线虫属（399只中有164只；41%）以及膀胱中的粗尾毛形线虫（194只中有59只；30%）。肿瘤性、先天性和退行性病变很少见，这可能反映了它们对城市环境中生存的不利影响。我们的结果建立了野生城市大鼠预期病变的基线，这可能对城市大鼠和人畜共患病原体生态学以及全球城市的鼠害控制具有重要意义。
