First described as “an apparently new transmissible disease of cattle” in 1946 [1], bovine viral diarrhea virus (BVDV) has become one of the most widespread viral pathogens of cattle. Since 2007, bovine viral diarrhea has been listed by the International Ofce of Epizootics as a reportable disease of cattle. Despite its moniker, the effects of BVDV infection are manifested not only in the gastrointestinal tract but also in the respiratory, reproductive, cardiovascular, lymphatic, immune, integumentary, or central nervous systems [2] of cattle, as well as several domestic and feral mammalian species of the order Artiodactyla [3]. The virus is responsible for a wide variety of clinical syndromes, but infection may also be subclinical or asymptomatic, emphasizing the need for accurate and efcient diagnostic tests. This is especially true in the case of persistent infection, where animals may appear phenotypically normal but consistently shed high amounts of live virus, playing a signicant role in the epidemiology of the virus. The clinical and economic

importance of BVDV as a livestock pathogen demands fast and accurate diagnostic tests at both the herd and individual animal levels.