New Shamonda virus strain – what you need to know

In adult cattle, reported signs include:

• A sudden rise in body temperature, sometimes above 40C (104F).
• Reduced feed intake and rumination.
• Loose, mushy or watery diarrhoea.
• A sudden and sometimes marked drop in milk yield.
• Abdominal distension or discomfort and reduced rumen fill.
• General loss of herd performance.

Neurological signs have now been described in SHAV-positive horses in Germany and Switzerland. Detecting the virus does not confirm it caused the illness, but horses with severe drowsiness, poor coordination or other neurological signs need urgent veterinary attention.

There is no vaccine currently available and no antiviral treatment that eliminates SHAV. Management is supportive and should be directed by the farm veterinary surgeon.

Advice on how to manage SHAV on farms includes:

• Triage according to urgency, using sensor data alongside examination of demeanour, appetite, milk yield, rumen fill, rumination and faeces.
• Use anti-inflammatory, antipyretic and analgesic medicines only under veterinary direction, observing contraindications and withdrawal periods.
• Investigate persistent rumination loss, mastitis, metabolic disease or other suspected secondary conditions rather than assuming all signs are caused by SHAV. 
• Support feed intake through excellent feed hygiene, frequent feed presentation and access to palatable, fibre-rich forage. Ensure adequate mineral provision where appropriate.
• Provide plentiful clean, preferably cool drinking water, with enough well-distributed trough space for hot conditions.
• Reduce heat load using effective ventilation and, where suitable, combined water cooling and fans. Avoid creating persistently high humidity.

Measures to reduce animals' exposure to biting midges may not prevent every infection, but they can help lower the risk. As part of a farm-specific plan, farmers may wish to consider approaches used for other midge-borne diseases:

• Use authorised repellents or insecticides according to the product label and veterinary advice.
• Maintain continuous, effective airflow where practical as strong air movement may reduce midge landing as well as relieve heat stress.
• Consider housing during peak midge activity, especially around dusk and overnight, while recognising that housing alone is not completely protective.
• Reduce local midge breeding opportunities where this can be done safely and practically, and review farm drainage and standing-water management.

Viruses similar to SHAV can sometimes infect a pregnant animal and affect the unborn offspring through abortion, stillbirth or congenital abnormalities.

SHAV has been associated with pregnancy losses and birth defects in livestock. However, it is not yet known how often the current European strain causes these problems or at what stages of pregnancy animals are most vulnerable.

Farmers should record and investigate abortions, stillbirths and malformed calves, lambs or kids with their veterinary surgeon.

Farmers and livestock keepers can help protect animal health by taking the following precautions and monitoring measures:

• Monitor cattle, sheep, goats, camelids and horses for unusual febrile, digestive, production or neurological signs.
• Contact a veterinary surgeon promptly if several animals develop fever, diarrhoea or sudden milk loss, or if any horse shows neurological signs.
• Arrange appropriate diagnostic sampling in consultation with the veterinary surgeon; do not rely on sensor alerts alone.
• Record illness, milk loss, reproductive events, treatments and recovery. These data may be valuable while formal surveillance remains incomplete.
• Keep breeding and pregnancy risks under review, especially during periods of high midge activity.
• Follow official UK animal-health updates. As at 2 September 2026, no SHAV-specific UK guidance was identified on GOV.UK, but APHA monitors new and emerging international animal disease threats.