Hemorrhagic disease caused by bovine viral diarrhea virus-2a in Korean Indigenous Cattle: case reports

Bovine viral diarrhea virus (BVDV), which is prevalent worldwide, is one of the most important viral pathogens and causes substantial economic loss to the livestock industry. Despite its importance, BVDV is largely unnoticed in the Republic of Korea (ROK). In this study, we report the case of a steer with BVDV that died suddenly due to severe enteritis. Two 1-year-old Korean indigenous cattle in the same herd presented severe hemorrhagic diarrhea. Case 1 had severe dehydration and died after 3 days, whereas case 2 had anorexia, depression, and severe diarrhea with mucus and blood. Only case 2 was necropsied, and BVDV2a was detected in the tissues of its alimentary tract. Gross lesions, including erosion, ulceration, and extensive hemorrhage, were observed in the digestive tract mucosa. Immunohistochemistry revealed marked positive staining for BVDV2a antigen in the large intestine. This report describes the first case of hemorrhagic disease caused by acute BVDV2a infection, which is characterized by high mortality in Korean indigenous cattle. This study will help establish vaccination and control strategies for BVDV in the ROK.