Bovine Viral Diarrhoea .

Bovine Viral Diarrhoea is a highly infectious disease caused by a virus transmitted from infected animals. BVD is widespread amongst herds and many farmers are unaware of the virus circulating in their herds. The signs of infection vary and majorly include fertility problems such as abortions and birth defects, scour and reduced milk yield. Other less directly associated illnesses, due to the effects of infection on the animals’ immune response, include an increased incidence of other diseases such as pneumonia, lameness or mastitis within the herd. BVD is spread by nose-to-nose contact between infected cattle within the herd, mixing with infected animals from another farm, and during transportation. Cattle can also be infected indirectly by exposure to contaminated equipment, other ruminants especially sheep or by visitors to the farm. Bio security protocols are important to ensure safety of herd and prevent infection. The infection type could be persistent or transient,where the transient infection occurs any time after the animal is born and the persistent type occurs when a dam is infected with BVD for the first time during the first 4 months of pregnancy and the developing calf born is persistently infected with the virus and sheds high levels of virus thereby been a ready source of virus on the farm. The control measure is to test herd and remove carriers,vaccination is major key to a safe and clean herd. Vaccination of dams before breeding season is important.