Major cardiac defects in cattle in southern Brazil: retrospective study of necropsies over 20 years (2000-2019)

ABSTRACT: Cardiac malformations are reported to be relatively rare in bovine species, with ventricular septal defects being the most common abnormality observed predominantly in young calves. This report aims to describe the cardiac malformations observed in bovids and review the literature related to those malformations in this species. The necropsy reports of 1,783 bovids were reviewed, and 0.4% were diagnosed with a cardiac congenital defect. The most common cardiac congenital malformation detected in this study was ventricular septal defect, observed alone or associated with other anomalies (in one case, as part of tetralogy of Fallot); followed by atrial septal defect, also alone or with other cardiac malformations. Secondary findings in the lungs and liver were observed in 75% of all cases. Histologic cardiac lesions were identified in 25% of all cases, characterized mainly by fibrosis. Other congenital malformations in different organs were observed in 25% of the cases. Considering the importance of cardiac congenital malformations observed in this study, these conditions should be considered as a differential diagnosis for calves who died with no specific clinical signs. Furthermore, macroscopic evaluation is crucial for the diagnosis of cardiac congenital malformations.

摘要：据报道，牛科动物的心脏畸形相对少见，其中室间隔缺损（ventricular septal defect）为最常见的畸形类型，且主要发生于幼龄犊牛。本研究旨在描述牛科动物的心脏畸形病例，并综述该物种心脏畸形的相关研究文献。本研究回顾了1783例牛科动物的尸检报告，其中0.4%被确诊患有先天性心脏畸形。本研究检出的最常见先天性心脏畸形为室间隔缺损，可单独存在或合并其他异常（1例作为法洛四联症（tetralogy of Fallot）的组成部分出现）；其次为房间隔缺损（atrial septal defect），同样可单独出现或合并其他心脏畸形。所有病例中，75%存在肺与肝脏的继发病变；25%的病例可见组织学层面的心脏病变，主要表现为纤维化；25%的病例存在多器官其他先天性畸形。鉴于本研究中检出的先天性心脏畸形具有重要临床意义，对于无特异性临床症状死亡的犊牛，应将此类病症纳入鉴别诊断范畴。此外，肉眼大体检查对于先天性心脏畸形的诊断至关重要。