Abstract:
Hepatic trematodes, such as Fasciola hepatica and Fascioloides magna, have variable distribution throughout the United States. F. magna is endemic in the upper midwestern United States, and F. magna infections are diagnosed frequently in weaned calves and adult beef cattle at the North Dakota State University Veterinary Diagnostic Laboratory (NDSU-VDL). Rarely, liver fluke infestation has also been observed in much younger calves, including aborted fetuses. We describe here, in 2 fetal and 7 neonatal beef calves submitted to the NDSU-VDL between 2011 and 2020, parasitic migration tracts in livers, consisting of regionally extensive, random, linear tracts of fibrosis admixed with black porphyrin pigment, along with foci of necrosis and hemorrhage, and mixed inflammatory cells, which were caused presumptively by F. magna infection. Samples were not available from our 9 cases for PCR assay and sequencing, but we did confirm F. magna within liver samples collected from regional cattle in 2020 and 2021. Fetal and neonatal trematodosis was often concurrent with other common causes of fetal abortion and neonatal calf loss in our cases; however, based on the prepatent period of F. magna, fetal and neonatal beef calf trematode infestations occurred in utero.
摘要:
肝吸虫,如肝片吸虫和麦片,在整个美国都有可变的分布。F.麦格纳在美国中西部上部流行,在北达科他州立大学兽医诊断实验室(NDSU-VDL),断奶的小牛和成年肉牛中经常被诊断出F.magna感染。很少,在更年轻的小牛中也观察到肝吸虫感染,包括流产的胎儿.我们在这里描述,在2011年至2020年期间提交给NDSU-VDL的2个胎儿和7个新生儿牛犊中,肝脏中的寄生虫迁移束,包括区域广泛,随机,与黑卟啉色素混合的纤维化的线性束,连同坏死和出血的病灶,和混合的炎症细胞,推测是由F.magna感染引起的。我们的9例病例中没有用于PCR分析和测序的样本,但我们确实在2020年和2021年从区域牛收集的肝脏样本中确认了麦格纳。在我们的病例中,胎儿和新生儿吸虫病通常与胎儿流产和新生儿小腿丧失的其他常见原因同时发生;然而,根据麦格纳的专利期,胎儿和新生儿牛犊吸虫感染发生在子宫内。