Shamonda virus reaches cattle herds in Great Britain
Shamonda virus has now been confirmed in cattle on two dairy farms in Great Britain, one in Powys, Wales and one in Shropshire, England. The detections followed sampling and laboratory testing at APHA facilities in Weybridge, and the affected cattle showed clinical signs consistent with acute cases described elsewhere in Europe. For veterinary teams, the significance is immediate: a vector-borne orthobunyavirus with livestock impact has moved into routine differential diagnosis for sick adult dairy cattle across parts of England, Scotland and Wales.
The virus belongs to the Simbu serogroup and is closely related to Schmallenberg virus. That relationship matters because it points toward a similar transmission ecology, clinical pattern and herd-level risk. Culicoides biting midges are believed to carry SHAV, just as they transmit SBV and bluetongue virus. Once that vector pathway is established in a region, disease recognition becomes harder in the field, because early clinical signs can look like a wide range of common production and infectious disorders.
Acute herd disease in adult dairy cattle
The clinical picture described in affected countries has centered on adult dairy cattle, often involving multiple animals in a herd over a short interval. Reduced rumination, lethargy, inappetence, a sudden drop in milk yield, transient fever and diarrhoea or scour make up the main syndrome. In a milking herd, those changes can appear abruptly enough to resemble nutritional upset, mastitis-associated production loss, respiratory disease, or a notifiable vector-borne infection. The pattern of several animals becoming ill in close succession is especially important, because it raises the probability of a shared infectious or arthropod-driven exposure rather than an isolated metabolic event.
The present alert also makes clear that reproductive disturbance has already accompanied acute clinical disease in affected herds. Return to service and abortion have been observed. For farm veterinarians, reproductive loss and production loss can arrive together, creating a deeper economic hit than a short febrile illness alone would suggest. A herd may first present with reduced milk output and off-feed cows, only for breeding performance to deteriorate later, when the vector exposure is no longer top of mind.
Congenital disease is the other major concern. In-utero SHAV infection has been associated with arthrogryposis, torticollis, scoliosis and brain malformations including hydranencephaly, porencephaly and cerebellar hypoplasia in calves and lambs. Those lesions fit a developmental timing problem rather than a simple postnatal infection. When a virus disrupts fetal neurologic and musculoskeletal development, the surviving newborn may show fixed deformities at birth, while pregnancy loss may occur earlier in gestation.
A single infected herd can therefore present across a wide temporal arc: acute adult illness, breeding disruption, and malformed offspring. Few infections in ruminants create that combination so efficiently.
Why the vector pathway raises the stakes
Culicoides transmission changes how a veterinary service has to think about case finding. A midges-borne virus does not require animal-to-animal contact in the ordinary sense; spread can follow seasonal vector activity and local ecology. That makes geographic clustering and time of year clinically relevant, especially when similar signs appear in more than one animal at once. The same mechanism that drives bluetongue and Schmallenberg spread can allow a virus to surface in regions where it was not previously recognized, then move quietly through susceptible herds before congenital abnormalities reveal the extent of exposure.
The relationship to Schmallenberg also provides a practical diagnostic shortcut. Veterinarians already understand how SBV can present, how congenital abnormalities may appear, and why herd surveillance matters. SHAV should now sit in that same mental space. Differential diagnosis cannot stop at the obvious production disease explanations, because the overlapping syndrome includes notifiable conditions such as bluetongue.
Testing guidance and field response
For cattle, sheep or goats in England and Wales with compatible signs, APHA advises contact with the local surveillance pathology centre to discuss investigation. Free-of-charge SBV and SHAV testing is being provided from October 2026 to May 2027 for calves, lambs and kids with arthrogryposis or other congenital musculoskeletal abnormalities. A fresh brain sample, with brainstem preferred, should be submitted and testing for both SBV and SHAV requested on the APHA submission form.
The sampling advice is clinically important because congenital cases are often the most specific signal of vector-borne teratogenic infection. Fresh tissue increases the chance of useful virologic testing, and the brainstem preference reflects the neurologic component of the syndrome. In practical terms, this means malformed newborns should not be treated as isolated anomalies until an infectious cause has been considered and documented.
Field clinicians also need to keep the notifiable disease pathway open. The clinical signs of SHAV are not specific to the virus and can overlap with several other diseases, some of them notifiable, including bluetongue. Suspicion of notifiable disease must be reported: in England by calling 03000 200 301, in Wales 0300 303 8268, and in Scotland 03000 600 704.
Public health risk remains low for people
UKHSA’s rapid risk assessment places SHAV at very low risk to the general population in the UK at the current time, and there is no evidence of a food safety risk. That distinction matters for messaging to farmers, veterinarians and consumers alike: the principal concern is animal health, herd productivity and reproductive loss, not human illness from food exposure. A full assessment is being undertaken by the Human Animal Infection and Risk Surveillance group, but the immediate operational response remains centered on livestock surveillance and timely reporting.
The current alert also extends the geographical frame. Detections across several European countries in 2026 have already involved cattle, sheep, goats, alpacas and horses, and the Great Britain cases fit a broader regional pattern of emergence. Vets working in ruminant practice will need to keep SHAV in the differential whenever adult dairy cattle show acute multi-animal illness, or when malformed calves and lambs suggest a teratogenic virus circulating through the breeding season.
For now, the most concrete action is simple: recognize the syndrome early, sample correctly, and report promptly when notifiable disease enters the frame. The unanswered question is not whether SHAV can affect livestock, but how widely it may establish itself in Great Britain’s vector season and what burden of congenital disease will follow if detection lags.