Border disease or hairy shaker disease is a virus which causes birth defects, barren ewes and abortion. It is from the same family of viruses as BVD in cattle.
If a ewe is infected during pregnancy the virus passes through the placenta to the lamb, in some cases this causes embryonic loss or abortion. Some lambs survive and are born Persistently infected (PI). PIs shed the virus continuously and can infect other sheep and lambs. This can be a major problem in naïve flocks unknowingly buying in PIs which can then cause around half of lambs born to be affected by the disease.
- Infection in non-pregnant adult sheep is generally short lived and mild, often no clinical signs are seen.
- Hairy shakers are lambs infected with the virus whilst developing in-utero effecting their nervous system which leads to trembling and incoordination. They also have long curly wool.
- Some lambs are born completely normal but maintain the infection, these are called Persistently Infected animals (PI).
Hairy shakers are usually a good way to diagnose the presence of the disease. These lambs can also be blood tested to confirm presence of the virus.
Blood testing a group of ewes can identify if the flock has been exposed to the disease and is likely to be present.
To discuss with our Farm Team further, please contact us