Prediction of the likely histopathological diagnosis of canine splenic masses can guide appropriate decision‐making. This study explores the predictive effect of breed and clinical presentation on the diagnosis of a canine splenic mass. Records from the Royal Veterinary College, United Kingdom (2007‐2017) were reviewed. Dogs with a histopathologic or cytologic diagnosis from a splenic mass, or imaging findings consistent with disseminated metastatic disease, were included. Signalment, physical examination, haematology results, imaging findings and pathology reports were recorded. Breeds were grouped according to several permutations of their phenotype and then by clustering of breeds based on single nucleotide polymorphism analysis. Binary logistic regression was performed to identify predictors of malignancy and haemangiosarcoma. Two hundred and eighty‐eight dogs were identified: 27% female and 63% male, 21% entire and 79% neutered; German Shepherd was the most common breed (11%). Median age was 10 years and median bodyweight 25 kg. Thirty‐eight percent of dogs presented with haemoabdomen; a splenic mass was found incidentally in 28%. Sixty percent had a malignant tumour of which haemangiosarcoma comprised 66%. On multivariable analysis, genotype‐based breed group (P = .004), haemoabdomen (P < .001) and neutrophil count (P = .025) predicted malignancy, and genotype‐based breed group (P < .001) and haemoabdomen (P < .001) predicted haemangiosarcoma. Genotype‐based breed group and occurrence of haemoabdomen may have predictive value to diagnose malignant splenic masses and more specifically haemangiosarcoma. The effect of genotype‐based breed grouping was a superior predictor of the diagnosis of a canine splenic mass lesion compared with all phenotype‐based groupings tested.

中文翻译：

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完善“双三分之二”规则：基于基因型的品种分组和临床表现有助于预测 288 只犬的犬脾肿块病变的诊断。

预测犬脾肿块可能的组织病理学诊断可以指导适当的决策。本研究探讨了品种和临床表现对犬脾肿块诊断的预测作用。审查了英国皇家兽医学院 (2007-2017) 的记录。包括脾肿块组织病理学或细胞学诊断或影像学检查结果与播散性转移性疾病一致的犬。记录信号、体格检查、血液学结果、影像学发现和病理报告。根据其表型的几种排列对品种进行分组，然后根据单核苷酸多态性分析对品种进行聚类。进行二元逻辑回归以确定恶性肿瘤和血管肉瘤的预测因子。确定了 288 只狗：27% 雌性和 63% 雄性，21% 整只和 79% 绝育；德国牧羊犬是最常见的品种（11%）。年龄中位数为 10 岁，体重中位数为 25 公斤。38% 的狗出现血腹；28% 的患者偶然发现了脾脏肿块。60% 患有恶性肿瘤，其中血管肉瘤占 66%。在多变量分析中，基于基因型的品种组（P = .004)、血腹 ( P  < .001) 和中性粒细胞计数 ( P = .025) 预测恶性，基于基因型的品种组 ( P  < .001) 和血腹 ( P  < .001) 预测血血管肉瘤。基于基因型的品种组和血腹的发生可能对诊断恶性脾肿块，更具体地说是血管肉瘤具有预测价值。与所有测试的基于表型的分组相比，基于基因型的品种分组的效果是诊断犬脾肿块病变的优越预测因子。