Bovine Viral Diarrhea Virus (BVDV) in cattle: Health impacts, reproduction, and management strategies

Abstract

Bovine Viral Diarrhea Virus (BVDV) is a significant pathogen for the cattle industry worldwide, significantly impacting animal health, reproduction, and economics. This virus belongs to the Pestivirus genus in the Flaviviridae family and has a positive-sense, single-stranded RNA genome. BVDV can infect lymphoid cells, hepatocytes, and mucosal epithelium, resulting in systemic disorders, immunosuppression, and the emergence of persistently infected (PI) animals, which serve as the primary reservoir for viral transmission. BVDV infection can be acute or chronic, with clinical symptoms varying depending on the immune status, age, and gestational stage of the animal. Adult cattle tend to experience subclinical infection, while calves are more susceptible to diarrhea, dehydration, thrombocytopenia, and high mortality. In pregnant cows, infection can trigger abortion, the birth of fetuses with congenital defects, or the birth of PI animals. The genetic diversity of BVDV, including non-cytopathic and cytopathic biotypes, as well as BVDV-1, BVDV-2, and HoBi-like (BVDV-3) genotypes, influences virulence, immune response, and vaccination success. Virus transmission occurs horizontally through direct contact, secretions, and contaminated environments, and vertically through transplacental infection. Risk factors include the presence of infected animals, housing density, low biosecurity, and uncontrolled reproductive practices. The economic impact of BVDV is significant, including reduced milk production, beef cattle growth, reproductive efficiency, abortions, and herd control costs. Control strategies emphasize identification and elimination of infected animals, planned vaccination, biosecurity implementation, and sound reproductive management. This review aims to provide a comprehensive understanding of BVDV, including etiology, pathogenesis, clinical manifestations, risk factors, diagnosis, and control strategies, as a basis for effective herd management and mitigating the economic impact on the cattle industry.