Giles R C, Tramontin R, Kadel W L, Whitaker K, Miksch D, Bryant D W, Fayer R
J Am Vet Med Assoc. 1980 Mar 15;176(6):543-8.
Sarcocystosis was diagnosed in 41 eighteen-month-old heifers and steers. Clinical signs included anorexia, severe weight loss, nervousness, hypersalivation, lameness, and hair loss on the extremities. Hair loss was noticed especially at the end of the tail, where there was complete loss of the switch, giving the animals a "rat-tail" appearance. Consistent gross changes observed at necropsy of four affected animals included generalized lymphadenopathy, erosions and ulcerations in the oral cavity and esophagus, and severe laminitis. Microscopically, young cysts of Sarcocystis sp were disseminated in the heart, skeletal muscle, and brain. Ultrastructural examination indicated that the cysts were young because they contained metrocytes. Affected animals had moderate to severe nonsuppurative myocarditis and myositis, with focal degeneration of myofibers and infiltration by macrophages, lymphocytes, and plasma cells. Indirect hemagglutination of sera from 19 animals revealed a mean antibody titer of 1:24,000 against Sarcocystis bovicanis antigen. Epidemiologic investigation incriminated resident farm dogs that had been housed in a farm hayloft as the source of infection. Hay contaminated with sporocysts in dog feces was thought to have been fed to the heifers and steers.
在41头18月龄的小母牛和公牛中诊断出了肉孢子虫病。临床症状包括厌食、严重体重减轻、神经质、流涎过多、跛行以及四肢脱毛。尤其在尾巴末端发现脱毛，尾梢完全脱落，使动物呈现出“鼠尾”外观。对4头患病动物进行尸检时观察到的一致大体变化包括全身性淋巴结病、口腔和食管的糜烂与溃疡以及严重的蹄叶炎。显微镜下，肉孢子虫属的幼囊散布于心脏、骨骼肌和大脑中。超微结构检查表明这些囊肿是幼囊，因为它们含有母细胞。患病动物患有中度至重度非化脓性心肌炎和肌炎，伴有肌纤维局灶性变性以及巨噬细胞、淋巴细胞和浆细胞浸润。对19只动物血清进行的间接血凝试验显示，针对牛肉孢子虫抗原的平均抗体滴度为1:24,000。流行病学调查认定，饲养在农场干草棚中的常住家犬为感染源。被犬粪便中孢子囊污染的干草被认为喂给了小母牛和公牛。
