Experienced veterinarians have warned that an outbreak of a potentially fatal livestock disease is likely to recur next year.

A new strain of the bluetongue virus, spread by midges, has affected much of eastern England in recent months.

There have also been two isolated cases in North Wales, caused by animal movements before restrictions came into force.

Dr Sioned Timothy, who leads pharmaceutical giant Boehringer Ingelheim’s livestock veterinary team in the UK, said the potential impact would be huge in Wales if the move came to fruition.

While midge activity is expected to decrease over the winter months, farmers are urged to remain vigilant for signs of infection, which do not affect people or food safety.

“We may be lucky that time is on our side and this season the spread of the virus is curbed,” explained Dr. Timothy.

His company is behind one of three newly developed vaccines that have not yet gone through the full authorization process but have been granted emergency authorization for use in England.

“We know from the experience of the Netherlands, where the epidemic was more widespread and the clinical signs were worse this year than in previous years, that it is likely to happen again,” he said. she declared.

“We need to look to the future and have a plan in place for what to do if the risk persists,” she added. “The main thing is that farmers are vigilant.”

The latest outbreak began in the Netherlands in 2023 and has spread widely across Europe this year, with midges from the continent infecting sheep and cattle in the UK.

A restricted arearestricting the movement of animals, is now in force in 20 counties in England, stretching from the south coast to parts of North Yorkshire.

Last week it was announced that the English Winter Fair – a major agricultural show – which was due to be held in Staffordshire in mid-November, had been cancelled.

Dr Timothy, who lives in Newcastle Emlyn, Carmarthenshire, said the “relatively low population numbers” in the east of England “will have limited the spread in some way”.

If the disease spread to Wales – where sheep and cattle farms dominate the agricultural landscape – “the potential impact would be huge”, she said.

The virus can cause ulcers or sores around the mouth and face, difficulty swallowing and breathing, fever and lameness.

Sheep are most affected by the latest strain, known as BTV-3, although the impact of the disease appears to vary widely between regions, with some animals showing few signs of infection.

In the Netherlands, tens of thousands of sheep died.

“We still face a potential unknown,” warned Dr. Timothy.

A total of 12 cases of BTV-3 have been detected so far outside the current restricted areas. These were all animals moved from areas where the disease is now known to be circulating before the restrictions came into force.

They include two cases in North Wales in recent weeks – involving three sheep on a farm in Gwynedd and an unidentified animal in Anglesey – all of which were culled.

Gwynedd Watkin, of the Farmers Union of Wales in Gwynedd, said the local community had been very concerned by the news.

“What reassured us was that the sheep affected by bluetongue had recovered, and also that the system of authorization of animal movements (made it possible) to trace the origin of the disease.”

“We encourage our members to be vigilant and take particular care about where they purchase their livestock,” he added.

Wales’ chief veterinary officer, Dr Richard Irvine, said investigations had been carried out at both sites to determine whether the virus had entered the midge population.

This work had been completed for Gwynedd’s first farm with no evidence of local bluetongue infection.

“We are working on monitoring the second farm and we hope it will give a similar result,” he said.

The disease was “very much” on the Welsh Government’s radar, he added, with officials “thinking very carefully about the coming weeks, months and into the spring”.

“I hope we will not see an increase in the severity of cases reported in northern Europe,” he said.

“But we certainly need to be prepared – while also taking immediate action here in Wales to be vigilant, report cases, source responsibly and protect the national stock from bluetongue.”

A group of stakeholders including agricultural and veterinary organizations had been meeting for several months to assess the situation, he said.

The potential role of new vaccines was part of this discussion, but these are currently “new products on the market” that are “not fully protective”, he added.

Dr Irvine and Dr Timothy warned that climate change could mean the disease becomes a more familiar problem in the UK.

“Historically, textbooks told us that bluetongue was a predominant disease in the Mediterranean basin several decades ago,” Dr Irvine said.

“We are certainly seeing a change in the pattern of many diseases as temperatures warm and seasons become less defined,” added Dr. Timothy.

“It is likely that the types of midges – for example – that are required to transmit some of these vector-borne diseases will become more prevalent.”

Bluetongue is a notifiable disease, so anyone suspecting the disease should report it to the Animal and Plant Health Agency (APHA).