Bovine Viral Diarrhea (BVD) or Bovine Viral Diarrhoea (UK English), and previously referred to as Bovine Virus Diarrhoea (BVD), is a significant economic disease of cattle which is endemic in the majority of countries throughout the world. The causative agent, bovine viral diarrhea virus (BVDV) is a member of the Pestivirus genus of the family Flaviviridae.