[BVD approach: vaccination and eradication]

The vulnerability of cattle populations that do not have adequate levels of antibodies against the bovine virus diarrhoea (BVD) virus was demonstrated in February 1999, when a contaminated vaccine against infectious bovine rhinotracheitis (IBR) was accidentally used. Only cattle with antibodies against BVD survived this unintentional challenge. A BVD infection can be detected easily with currently available laboratory techniques, but the virus is less easy to eliminate. The risk of financial loss is small, and the costs are limited, if mainly seronegative cattle, selected on the basis of sampling, are given the live vaccine. Over the last 7 years this approach has been applied to about twenty dairy farms. This approach would be compatible with a BVD eradication programme.