Teichner Sean R, Powell Lisa L, Mazepa Allison S
BluePearl Pet Hospital, Golden Valley, Minnesota, USA.
J Vet Intern Med. 2025 Sep-Oct;39(5):e70233. doi: 10.1111/jvim.70233.
A 4-year-old spayed female Golden Retriever was examined for hindlimb lameness, lethargy, poor appetite, and pyrexia 3 weeks after the removal of numerous ticks. Complete blood count revealed moderate thrombocytopenia and mild lymphopenia. A SNAP 4Dx test was negative for Borrelia burgdorferi, Ehrlichia spp., Anaplasma spp., and Dirofilaria immitis. Abdominal ultrasound identified moderate mesenteric lymphadenopathy and regionally hyperechoic mesentery. Joint fluid cytology raised concern for large cell lymphoma. Flow cytometry identified 37% aberrant large CD4+ T cells, suggesting lymphoma. PCR for antigen receptor rearrangement (PARR) testing on the joint fluid confirmed clonal expansion of T cells, further supporting T-cell lymphoma. Peripheral blood PCR was positive for Anaplasma phagocytophilum. The dog's clinical signs and laboratory abnormalities resolved after a 30-day treatment with doxycycline. After treatment, joint fluid analysis, including cytology and flow cytometry, was normal. This case highlights the importance of considering A. phagocytophilum as a differential diagnosis in dogs with a clonal expansion of CD4+ T cells, emphasizing the comprehensive diagnostic approach.
一只4岁已绝育的雌性金毛猎犬在拔除大量蜱虫3周后，因后肢跛行、嗜睡、食欲不佳和发热前来就诊。全血细胞计数显示中度血小板减少和轻度淋巴细胞减少。SNAP 4Dx检测对伯氏疏螺旋体、埃立克体属、无形体属和犬恶丝虫呈阴性。腹部超声检查发现中度肠系膜淋巴结病和局部高回声肠系膜。关节液细胞学检查引起了对大细胞淋巴瘤的关注。流式细胞术鉴定出37%异常的大CD4 + T细胞，提示淋巴瘤。对关节液进行抗原受体重排（PARR）检测的聚合酶链反应（PCR）证实了T细胞的克隆扩增，进一步支持T细胞淋巴瘤。外周血PCR检测嗜吞噬细胞无形体呈阳性。用强力霉素治疗30天后，犬的临床症状和实验室异常情况得到缓解。治疗后，包括细胞学和流式细胞术在内的关节液分析结果正常。该病例强调了在CD4 + T细胞克隆扩增的犬中，将嗜吞噬细胞无形体作为鉴别诊断的重要性，突出了综合诊断方法的重要性。
