Herd H R, Sula M M, Starkey L A, Panciera R J, Johnson E M, Snider T A, Holbrook T C
Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK, USA.
Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK, USA Current affiliation: Department of Biomedical and Diagnostic Sciences, Collage of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.
Vet Pathol. 2015 Nov;52(6):1191-4. doi: 10.1177/0300985815584073. Epub 2015 May 8.
This report describes 2 genetically related paint mares, case Nos. 1 and 2, presented to the Oklahoma State University Boren Veterinary Medical Teaching Hospital for chronic weight loss and abnormal gait, respectively. Notable findings in both cases included marked persistent eosinophilia and multiple intramuscular lateral thoracic masses. Histologic examination of masses revealed eosinophilic, centrally necrotic granulomas and marked eosinophilic myositis. Granulomas in case No. 1 also contained intralesional Sarcocystis sp material, and adjacent muscle fibers contained intact protozoal cysts. Case No. 1 developed severe refractory muscle pain and recurrent esophageal dysphagia. At necropsy, disseminated, grossly visible granulomas were present throughout all examined striated muscles. Nested polymerase chain reaction of the 18S rRNA gene revealed >99% homology with Sarcocystis fayeri. Sarcocystis spp are apicomplexan protozoa that infect striated muscle of many omnivorous species, typically without inciting clinical disease. Sarcocystosis should be considered a rare cause of granulomatous eosinophilic myositis and choke in horses.
本报告描述了两匹具有遗传相关性的花马，病例编号1和病例编号2，分别因慢性体重减轻和异常步态被送至俄克拉荷马州立大学博伦兽医学院教学医院。两例的显著发现均包括明显的持续性嗜酸性粒细胞增多和多个胸外侧肌内肿块。肿块的组织学检查显示嗜酸性、中央坏死性肉芽肿以及明显的嗜酸性肌炎。病例1的肉芽肿内还含有病灶内的肉孢子虫属物质，相邻的肌纤维含有完整的原生动物囊肿。病例1出现了严重的难治性肌肉疼痛和复发性食管吞咽困难。尸检时，在所有检查的横纹肌中均发现了弥漫性、肉眼可见的肉芽肿。对18S rRNA基因进行巢式聚合酶链反应，结果显示与费氏肉孢子虫的同源性>99%。肉孢子虫属是顶复门原生动物，可感染许多杂食性物种的横纹肌，通常不会引发临床疾病。肉孢子虫病应被视为马肉芽肿性嗜酸性肌炎和噎食的罕见病因。
