The genus Neorickettsia includes obligate, intracellular bacteria responsible for diseases including Potomac horse fever caused by Neorickettsia risticii and salmon poisoning disease (SPD) caused by Neorickettsia helminthoeca. The Stellanchasmus falcatus (SF) agent is a member of this genus previously associated only with mild clinical signs in dogs. Between 2013 and 2016, 3 dogs in Washington State (USA) presented with disease suggestive of SPD, but N. helminthoeca was not detected by molecular techniques. Clinical signs included depression, anorexia, and diarrhea. Cytologic examination of aspirates supported a diagnosis of granulomatous lymphadenitis with organisms suggestive of Neorickettsia. Dogs either died or were humanely euthanized due to poor response to therapy. Necropsy findings included lymphadenomegaly and hepatomegaly. Histopathology identified granulomatous and lymphoplasmacytic splenitis, lymphadenitis, enteritis, and hepatitis with extensive necrosis. Neorickettsia DNA was detected using genus-specific primers and direct sequencing showed 100% sequence identity to the SF agent in all 3 dogs. This is the first clinicopathologic description of severe disease in dogs attributed to the SF agent. These findings may suggest the emergence of a novel neorickettsial disease in the Pacific Northwest.

中文翻译：

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西北太平洋地区3只狗的新型新立克次体感染。

新立克次氏菌属包括专性的细胞内细菌，其引起疾病包括：由新立克次氏菌引起的波托马克马热和新立克次氏菌引起的鲑鱼中毒疾病（SPD）。Stellanchasmus falcatus（SF）药剂是该属的成员，以前仅与犬的轻度临床体征有关。在2013年至2016年之间，美国华盛顿州的3只狗表现出提示SPD的疾病，但分子技术未检测到N. helminthoeca。临床体征包括抑郁，厌食和腹泻。抽吸物的细胞学检查有助于诊断肉芽肿性淋巴结炎，并伴有提示新立克次体的生物。由于对治疗的不良反应，狗要么死亡要么被人道安乐死。尸检结果包括淋巴腺肿大和肝肿大。组织病理学鉴定为肉芽肿和淋巴浆细胞性脾炎，淋巴结炎，肠炎和肝炎，广泛坏死。使用属特异性引物检测新立克次体DNA，直接测序显示在所有3只狗中与SF试剂的序列同一性为100％。这是归因于SF剂的犬中严重疾病的第一个临床病理描述。这些发现可能表明在西北太平洋地区出现了一种新的新立克次体病。