Lymphoma is the most common haematological malignancy in dogs and its aetiology is largely unknown. The presence of canine vector‐borne agents (CVBD) in lymphoma tissues has been described and its causative effects questioned. We intended to evaluate the presence and extent of Leishmania infantum, Ehrlichia canis, Anaplasma phagocytophilum and Bartonella henselae infection in dogs with lymphoma. Sixty‐one dogs, living in the Lisbon metropolitan area, with a diagnosis of lymphoma were enrolled. Immunofluorescence assays were used to detect serum IgG's. The presence of DNA from CVBD agents in tumour tissue was assessed by PCR. All dogs tested negative for B. henselae, A. phagocytophilum and E. canis by both serology and PCR. Regarding L. infantum, 8.2% (n = 5) of the dogs had a positive serologic result. L. infantum DNA was detected in two samples of diffuse large B‐cell lymphoma (DLBCL). These results show an increased, but not significant, seropositivity (8.2% vs 7.9%) and molecular detection (3.3% vs 1.2%) for L. infantum in dogs with lymphoma, when compared to the reported canine population in the same geographical area. We could not identify an association between lymphoma and E. canis, A. phagocytophilum, B. henselae or Leishmania infantum infection in the studied population. Nevertheless, further studies, following dogs trough their CVBD disease evolution, are worthwhile and may help clarify a possible role of CVBD agents in lymphomagenesis.

中文翻译：

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犬淋巴瘤和媒介传播疾病：可能的共病的分子和血清学评估

淋巴瘤是犬最常见的血液系统恶性肿瘤，其病因在很大程度上是未知的。已经描述了在淋巴瘤组织中存在犬媒介传播的药物 (CVBD) 并对其致病作用提出质疑。我们打算评估患有淋巴瘤的狗中婴儿利什曼原虫、犬埃立克体、无形体吞噬细胞和亨氏巴尔通体感染的存在和程度。招募了 61 只生活在里斯本市区的诊断为淋巴瘤的狗。免疫荧光测定用于检测血清IgG。通过PCR评估肿瘤组织中来自CVBD试剂的DNA的存在。所有狗的 B 检测均为阴性。通体，A.吞噬细胞和E. canis通过血清学和 PCR。关于婴儿乳杆菌，8.2% (n = 5) 的狗具有阳性血清学结果。在两个弥漫性大 B 细胞淋巴瘤 (DLBCL) 样本中检测到婴儿乳杆菌DNA。这些结果显示，与报告的同一地理区域的犬类相比，患有淋巴瘤的犬中婴儿乳杆菌的血清阳性率（8.2% 对 7.9%）和分子检测（3.3% 对 1.2%）增加，但不显着。我们无法确定关联淋巴瘤之间和E.犬，A.吞噬细胞，B.通体或婴儿利什曼原虫研究人群中的感染。尽管如此，在狗经历其 CVBD 疾病演变之后的进一步研究是值得的，并且可能有助于阐明 CVBD 药物在淋巴瘤发生中的可能作用。