Bovine viral diarrhea virus (BVDV) is a common disease in cattle which causes significant economic losses around the globe. The severity of the negative financial impact of the virus varies based on the immunity status of a given population and the pathogenicity of the viral strain. In populations that are susceptible to BVDV or the introduction of a highly pathogenic strain, understandably will lead to high economic losses in that herd.
In breeding cattle, the virus causes reproduction disorders (abortion, prolonged gestation, reduced fertility) and has a negative impact on productivity because of culling, morbidity, and mortality. The disease could manifest as acute, subclinical, and persistent infection forms. All forms of BVDV cause health issues in affected herds and lead to the presence of persistently or temporarily infected animals. The circulation of the virus in the population is facilitated by the variety of forms that the disease can take, regardless of the presence of high viral antibodies.
The spread of the bovine viral diarrhea virus in dairy herds
The virus can cross the placenta and cause infection of the fetus early during pregnancy, resulting in the birth of persistently infected (PI) cattle. The most important sources of infection are the PI animals. On the other hand, healthy adult cattle or calves that become transiently infected (TI) are normally of a minor significance with regards to disease spreading.