Maedi Visna (MV) is a highly infectious viral disease affecting goats and sheep. It is mainly transmitted through the ingestion of milk from a virus infected sheep, although disease can be spread within flocks through direct contact or contamination. The virus does not affect people and therefore there is no impact on human health.

If notifiable disease is suspected, contact the DAERA Helpline on 0300 200 7840 or your local DAERA Direct Regional Office. Failure to do so is an offence

Latest Situation (July 2022)

Maedi Visna (MV) is currently widespread amongst sheep in most industrial countries, including Great Britain (GB). The Department of Agriculture Food and the Marine (DAFM) in the Republic of Ireland (ROI) has also reported two confirmed cases of MV. DAFM no longer considers its sheep population to be MV free. In the light of this, all breeding and production sheep imports from ROI will now be sampled on arrival in NI for the presence of the disease. This is effective from Monday 13 June 2022.

Following the detection of MV in Scotland during November 2021 in NI homebred sheep a substantial veterinary investigation is ongoing to identify the extent of the infection with a view to controlling this outbreak and eradicating the disease as effectively as possible.

Movement restrictions have been put in place and notices served on the affected holdings to restrict movements following tracing activity to prevent any movements on or off the farm while further testing and removal of any infected animal proceeds. Officials are currently working closely with stakeholders, SRUC and GB/ROI colleagues to determine next steps which will be informed by the ongoing epidemiological investigation.

What are the clinical signs?

MV is an infectious, incurable and very slow developing condition which causes wasting and failing. The main clinical signs are progressive paralysis, wasting, arthritis and chronic mastitis. MV has a long incubation period and cannot be detected early in an animal’s life. The signs are not normally visible until adulthood. 


Keeping NI free from MV is vital for our animal health and trading status. As part of its surveillance programme, the Department now samples any new arrivals into NI from outside the island of Ireland, for the presence of the disease. Animals imported from MV non accredited flocks in GB will be sampled in isolation 5 months after importation. Animals from MV accredited free flocks and from mainland Europe and from Republic Of Ireland (from 13 June 2022) will be sampled on arrival. 

The Department would urge farmers to think carefully before importing sheep from GB, ROI or mainland Europe and remember that

  • Any sheep coming into NI from GB must either be from a flock that is accredited free of disease, or
  • Have been held in isolation for 30 days and tested for MV, with negative results, prior to import. (These sheep will also have to move into a pre-approved isolation premises and undergo a test at 5 months post import.)

Animals subsequently found to be infected with MV will either be re-exported or slaughtered without compensation. Movement restrictions will also be placed on the holding.

MV is a notifiable disease. If you suspect disease you must inform your local DAERA Direct Office immediately. Failure to do so can be deemed an offence.

For further information specific to the import of sheep and goats, please see the following link:
Sheep and goat imports from GB | Department of Agriculture, Environment and Rural Affairs (

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