Multicavitary effusions were identified in an 18-year-old Tennessee Walking Horse gelding that had been losing weight throughout the previous 6 months. Based on results of microbiological culturing of peritoneal and pleural fluid, peritonitis and pleuritis were attributed to actinobacillosis. Whereas previous case reports indicate that most horses affected with actinobacillosis are typically presented with signs that include acute colic, fever, lethargy, inappetence and respiratory signs (dyspnoea, coughing or nasal discharge), and in which haematological abnormalities (leucocytosis, neutrophilia or leucopenia) are readily identified, the only abnormality in this case was progressive weight loss. The gelding made a complete recovery following drainage of fluid from both the peritoneal and pleural spaces and treatment with broad-spectrum antimicrobials. Peritoneal and pleural effusions were readily identified by ultrasonography, facilitating collection of fluid from which the diagnoses were established. Actinobacillosis should be considered in the differential diagnosis of weight loss in adult horses, even when typical clinical signs of acute peritonitis or pleuritis are not identified.

中文翻译：

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与体重减轻的成年田纳西步行马的放线杆菌病相关的多腔化脓性积液

一头 18 岁的田纳西步行马在过去 6 个月一直在减轻体重，发现多腔积液。根据腹膜和胸水的微生物培养结果，腹膜炎和胸膜炎归因于放线菌病。而之前的病例报告表明，大多数感染放线菌病的马通常会出现包括急性绞痛、发烧、嗜睡、食欲不振和呼吸系统症状（呼吸困难、咳嗽或流鼻涕）以及血液学异常（白细胞增多、中性粒细胞增多或白细胞减少）的症状很容易识别，在这种情况下唯一的异常是进行性体重减轻。在从腹膜和胸膜腔排出液体并用广谱抗菌剂治疗后，阉马完全康复。腹腔积液和胸腔积液很容易通过超声检查确定，有助于收集确定诊断的液体。在成年马体重减轻的鉴别诊断中应考虑放线杆菌病，即使未发现急性腹膜炎或胸膜炎的典型临床症状。