To determine if there were significant differences produced by 5 of the most prevalent causes of equine enterocolitis, we studied retrospectively the gross and microscopic pathology of 90 cases of enterocolitis submitted to the San Bernardino laboratory of the California Animal Health and Food Safety Laboratory. Included were cases caused by Clostridium perfringens type C (CP; n = 20), Clostridioides difficile (CD; n = 20), Paeniclostridium sordellii (PS; n = 15), Salmonella enterica subspecies enterica serovar Typhimurium (ST; n = 20), and NSAID intoxication (NS; n = 15). Grossly, necrotizing hemorrhagic typhlocolitis was seen most frequently in cases of CD, ST, and NS disease. Cases of CP and PS had enteritis or colitis in similar percentages. Congestion, hemorrhage, and pleocellular inflammatory infiltrates followed by mucosal and submucosal necrosis were the main lesions found in horses with enteritis or colitis produced by any of the etiologic agents investigated. Severe lesions were more frequent in cases of CD and CP than in cases associated with any of the other 3 etiologies. Pseudomembranes were observed with similar prevalence in the small intestine and colon affected by all agents studied. Thrombosis of the lamina propria and/or submucosa was observed in ~50% of the cases of enteritis and colitis by all etiologies, except for PS, in which the majority of the cases had thrombosis. Gross and microscopic lesions of enterocolitis were not sufficiently specific for any of these etiologic agents to enable these enteritides to be distinguished by gross and/or histologic examination.

为了确定 5 种最常见的马小肠结肠炎病因是否存在显着差异，我们回顾性研究了提交给加州动物健康和食品安全实验室圣贝纳迪诺实验室的 90 例小肠结肠炎的大体和微观病理学。包括由C 型产气荚膜梭菌(CP; n  = 20)、艰难梭菌(CD; n  = 20)、Paeniclostridium sordellii (PS; n  = 15)、肠沙门氏菌亚种肠鼠伤寒血清型 (ST; n  = 20)引起的病例, 和 NSAID 中毒 (NS; n = 15)。大体上，坏死性出血性肠炎最常见于 CD、ST 和 NS 疾病病例。CP 和 PS 病例患有肠炎或结肠炎的百分比相似。充血、出血和多细胞炎症浸润，随后是黏膜和黏膜下层坏死，是在任何研究的病原体引起的患有肠炎或结肠炎的马身上发现的主要病变。CD 和 CP 的严重病变比与其他 3 种病因相关的病例更常见。在受所有研究药物影响的小肠和结肠中观察到假膜具有相似的流行率。在约 50% 的肠炎和结肠炎病例中观察到固有层和/或黏膜下层的血栓形成，除了 PS，其中大多数病例有血栓形成。