Maedi Visna (MV) is a viral disease which was introduced into the UK through imported sheep. It has since spread, especially in commercial flocks.

MV is a chronic disease of sheep caused by a retrovirus. The name derives from two Icelandic words which describe the main clinical signs of pneumonia and wasting. The condition is highly contagious, difficult to diagnose and is fatal.

You can download here a vet presentation here that gives you details on MV and other sheep diseases. 

The Impact of MV

The main welfare and economic impacts of MV in a flock are

  • It is a fatal condition after development of clinical signs
  • There is increased lamb mortality and reduced growth rates
  • There is an increase in culling rate
  • There is increased incidence of arthritis, premature birth and reduction in conception

MV Accreditation

On behalf of DEFRA, SRUC run  an MV Accreditation scheme for flocks to certify that they are free from MV.

The MV Accreditation is under the auspices of the Premium Sheep and Goat Health Schemes

Downloads relating to the MV Accreditation scheme are available here –

Benefits of Joining the MV Accreditation Scheme

  • Helps reduce the risk of your flock contracting MV
  • Gives membership of a nationally recognised health scheme
  • Allows export to certain countries free from MV
  • Gives added value to the flock
  • Allows attendance at a wider range of shows and sales as some only allow MV animals to be present