The true cost of maedi visna virus (MVV) infection in a commercial flock

Maedi visna virus (MVV) infection is a chronic infectious disease of sheep that cannot be treated or prevented by vaccination. The main routes of transmission are through ingestion of infected colostrum and through nose to nose contact with infected stock. The virus can be introduced to a flock through the purchase of a single infected animal. MVV infection has the potential to cause major production losses, and once a flock is heavily infected it is difficult to control and eradicate. This article uses a real life case study to illustrate the impact of MVV in a commercial flock, and provides an overview of the disease along with practical advice on diagnosis and control.