NSA urges sheep farmers to stay alert as Shamonda virus reaches GB

National Sheep Association (NSA) is urging sheep farmers to keep reporting suspect disease in their flocks to their vet, following the first detections of Shamonda virus (SHAV) in Great Britain.

The midge-borne virus was identified on two dairy cattle farms Wales in October 2026, picked up by the Animal and Plant Health Agency (APHA) through disease surveillance. SHAV has spread through several European countries during 2026, mainly in cattle, with the most recent cases in Jersey and the Republic of Ireland.

SHAV is not a notifiable disease. However, livestock keepers should continue to monitor their animals for clinical signs and contact their vet if they have concerns, so animals can be treated as early as possible.

Phil Stocker, NSA Chief Executive, says: “Following hard on the heels of BTV3, a virus affecting sheep and cattle that is still very live here in GB, another exotic midge-borne virus has now been identified. Shamonda virus has been found in two cases Wales, picked up by APHA through disease surveillance. These cases were not unexpected, as the virus has been tracked across the EU and into the Channel Islands.

“The cases are concerning and are another symptom of changes in disease spread across the continent. They show the importance of our national surveillance, and of livestock keepers reporting unexpected and suspect cases of sick animals to their vets.

“These are very early days and keepers should not be overly alarmed. At least these two cases have appeared at a time of year when midge activity has slowed. NSA will keep members informed of developments.”

What it means for sheep

To date, acute disease has not been seen in sheep or goats. However, congenital abnormalities linked to SHAV have been described in Europe in both cattle and sheep following infection in the womb. Pregnant animals should be closely monitored, and any reproductive abnormalities investigated with a vet.

Clinical signs

Two main clinical presentations have been associated with SHAV.

1. Acute disease, described predominantly in adult dairy cattle, with several animals in a herd affected at the same time. Signs include:

• Reduced rumination.
• Loss of appetite.
• Lethargy.
• A sudden, temporary drop in milk yield.
• Acute diarrhoea, which may be foul-smelling.
• A short-lived high fever (above 40°C) lasting up to two days.
• Reproductive effects, including returns to service, abortions, increased rates of retained fetal membranes, metritis and endometritis.

The proportion of animals affected has varied, although some outbreaks have seen very high numbers affected within a herd, with clinical signs lasting about two to three weeks. No direct deaths have been described.

2. Congenital or fetal abnormalities, seen in cattle and sheep, including:

• Musculoskeletal deformities, including fixed joints (arthrogryposis), a twisted neck (torticollis) and curvature of the spine (scoliosis).
• Brain deformities, including hydranencephaly, porencephaly and cerebellar hypoplasia.

Treatment and prevention

There is no specific treatment for SHAV and no licensed vaccine. Management is limited to supportive veterinary care for animals showing clinical signs. Field experience from affected herds suggests early use of anti-inflammatory drugs may reduce the severity and length of illness in some animals. Preventing exposure to midges is difficult under field conditions.

Diagnostic testing is available through APHA, and vets investigating suspect cases can contact their local APHA Veterinary Investigation Centre.

Bluetongue remains a notifiable disease. Any suspicion must be reported immediately to APHA on 03000 200 301, or 0300 303 8268 in Wales. In Scotland, contact the local Field Services Office.