Bovine Virus Diarrhoea (BVD)
Summary written by Peter Nettleton MBE, BVMS, MSc, PhD, MRCVS
and Kim Willoughby BVM&S, PhD, MRCVS
Taken from Moredun Foundation Newsheet Volume 5 No. 20 (2013)
- Bovine Virus Diarrhoea (BVD) is a contagious disease of cattle occurring worldwide and many livestock farmers rate it among their highest economic and welfare concerns.
- BVD is caused by a pestivirus, bovine viral diarrhoea virus (BVDV) and is responsible for a range of different clinical outcomes, including infertility and reproductive problems, respiratory and gut disease and in some cases fatal mucosal disease.
- The main disease occurs when susceptible pregnant animals become infected with BVDV which can cross the placenta infecting and causing disease in the developing foetus.
- If infection occurs in the first half of pregnancy the foetus can die and be resorbed, presenting as infertility or ‘repeat breeding’. Sometimes infected foetuses die later and can be aborted right up to term or be stillborn. Many foetuses however survive to term. Some are damaged and grow poorly but most are apparently normal. All of them are persistently infected (PI) with the virus, which is widespread in their bodies.
- Once their BVDV colostrum-derived antibodies have waned, PI calves excrete virus continuously for the rest of their lives. They may develop mucosal disease (a fatal enteric disease) at any age. If a PI cow breeds successfully she will always produce a PI calf.
- BVDV infection is spread and maintained through the existence of PI animals, which constantly excrete the virus. They will rapidly infect other cattle that are in close contact.
- Cattle which are transiently infected after birth cannot become persistently infected but their immune systems can be temporarily dampened down by BVDV making calf pneumonia and scour more severe. Sometimes a particularly virulent strain of BVDV can cause severe illness and death.
- Bulls infected with the virus may become infertile for several months and can transmit the virus to susceptible cows in their semem.
- Control and prevention of the infection can be achieved by applying strict biosecurity procedures, vaccination and long term control strategies. Several countries have successfully eradicated BVD.
The full news sheet for any of the disease summaries can be ordered from the Moredun Foundation by using the following request form. The first news sheet title requested is free*, further news sheet titles are charged at £5.00 per copy (including postage).
*offer limited to one news sheet title per postal address in any one year. After that each news sheet will be charged at the standard price of £5.00 (including postage).
Moredun Membership Scheme
Moredun runs a membership scheme which aims to keep farmers and their vets up to date with the latest developments in animal health research. If you are interested in becoming a member of the Moredun Foundation, please click here.