As the drive to be BVD free in the UK moves forward, MSD Animal Health is offering reassurance to farmers using Bovilis® BVD, that this BVD vaccine brand will not confuse the results of standard BVD PCR testing (e.g ‘tag and test’). An inactivated BVD strain is used in the vaccine which cannot be transferred from the dam to the foetus.

Andrew Montgomery, veterinary advisor for MSD Animal Health explains the importance of ear tag testing: “When it comes to BVD control, at a practical farm level we strongly recommend two crucial steps. Firstly, to find the persistently infected (PI) calves and remove them. Secondly, to prevent any more PI calves being born.

“Farmers can find new-born PI calves by testing ear notch samples. If a live BVD vaccine is used, then the vaccine strain may be passed to the foetus, giving a positive result to standard ‘tag and test’ PCR screening. As with any positive test, farmers must wait three to four weeks during retesting to see if the virus clears and possibly undertake more detailed virus screening - this can cause confusion and anxiety. Further testing establishes whether the results are from the vaccine strain or a new case of the field strain.

“To prevent any more PI calves being born, heifers should be vaccinated. This is important in curbing the spread of BVD, as avoiding PIs being born is key to breaking the cycle of disease. Bovilis® BVD boosters can be used safely at any time during pregnancy, providing foetal protection. The primary course consists of two vaccinations given four weeks apart to cattle over the age of eight months, to be completed four weeks before pregnancy. The first booster is given six months later, then at 12-month intervals."