对一只8岁的萨南山羊母羊进行了检查，其表现为食欲不振、心动过速以及口腔黏膜间歇性的灰蓝色变。在体格检查中，发现这只羊轻度呼吸急促和心动过速，而在胸腔左侧听诊时听到的声音减弱。选择了安乐死。尸检发现在胸腔左侧有一块浸润性多结节的肿块，并散布在肺膜、胸腔壁和膈肌上的无数小块棕色结节。组织学检查显示这块肿块由高度多形性的梭形至多角形细胞组成。肿瘤细胞对细胞角蛋白和促膜蛋白呈阳性免疫反应，与双相胸膜间皮瘤的诊断一致。关键临床信息：虽然羊中极少见到有胸膜间皮瘤的报道，但是在小反刍动物的胸腔肿块的鉴别诊断中应考虑该病，在此基础上需考虑胸腺瘤、转移性肿瘤、癌肉瘤以及由寄生虫、细菌与真菌引起的肉芽肿性病变。加拿大兽医医学协会拥有版权和/或出版权。

An 8-year-old Saanen goat doe was seen for inappetence, tachycardia, and intermittent bluish-grey discoloration of the oral mucous membranes. On physical examination, the goat was mildly tachypneic and tachycardic, with reduced sounds auscultated on the left side of the thorax. Euthanasia was elected. Necropsy revealed an infiltrative, multinodular mass within the left thoracic cavity and innumerable small, tan nodules disseminated across the pleura of the lungs, thoracic walls, and diaphragm. Upon histologic examination, the mass was composed of highly pleomorphic, fusiform to polygonal cells. Neoplastic cells exhibited positive immunoreactivity for both cytokeratin and vimentin, consistent with a diagnosis of biphasic pleural mesothelioma. Key clinical message: Mesothelioma has rarely been described in the goat but should be considered as a differential diagnosis for thoracic masses in small ruminants, along with thymoma; metastatic neoplasia; carcinomatosis; and granulomatous lesions caused by parasites, bacteria, and fungi.Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.