Border disease is a syndrome of sheep caused by pestiviral infection, most commonly by border disease virus (BDV), but also by bovine viral diarrhoea virus (BVDV). Border disease results in a varied spectrum of clinical signs, but most commonly increased barren rates, abortion, stillbirths and the birth of weak lambs. Outbreaks of acute severe clinical disease in adult sheep are rare, but have been reported. There is increasing evidence of its negative impact on lamb health and growth rates through its immunosuppressive effects. There is currently little knowledge on how widespread border disease is within the British sheep industry and how much of an effect it is having on flock health and productivity.

James Patrick Crilly - Larkmead Veterinary Group, Ilges Lane, Cholsey, Oxon, OX10 9PA

Amy Jennings - University of Edinburgh, Easter Bush, Midlothian, EH25 9RG

Emily Gascoigne - Synergy Farm Health Ltd., West Hill Barns, Evershot, Dorset, DT2 0LD