Economic impact of BVDV infection in dairies.

The detrimental effects of bovine virus diarrhoea virus (BVDV) infections include reduced milk production, reduced reproductive performance, growth retardation, increased occurrence of other diseases, unthriftiness, early culling and increased mortality among young stock. These losses have been documented in several case descriptions and to some extent quantified in epidemiological studies. The detrimental effects together with information on population structure, incidence of infection and monetary value of production losses have been included in different models for estimating economic losses and benefits of different control strategies. This paper reviews different studies and methods for estimating economic losses and the economic effect of control strategies on both the local herd level and the national herd level. The estimated losses in individual herd outbreaks have varied from a few thousand up to $100000. There seems to be no universal truth for determining most optimal strategy at the herd level as it depends on herd-specific conditions. Most estimations of the losses at the national level range between 10 and 40 million $ per million calvings. In the few countries that have introduced eradication campaigns, the programmes have been shown to be cost effective. However, selection of a control strategy should always rely on thorough epidemiological investigations conducted under the same conditions in which the programme is going to be applied.