Keep watch for bluetongue virus during winter months

Livestock producers are urged to remain vigilant following the discovery of bluetongue in cattle on a Norfolk farm last month.

A 10km temporary control zone was declared around the premises near Cantley, Broadland. Two infected animals were culled and livestock movement restrictions imposed to minimise the risk of onward transmission.

The discovery came after government vets conducting their annual bluetongue surveillance programme last November identified a case of the disease in Kent. The Norfolk case is the first in East Anglia.

Notifiable disease

Bluetongue virus is a notifiable disease which must be reported to the Animal and Plant Health Agency by law. Temporary control zones are in place around all affected farms, restricting the movement of susceptible animals except under licence.

Chief veterinary officer Christine Middlemiss said: “Bluetongue does not pose a threat to human health or food safety, but the disease can impact livestock farms, and cause productivity issues.”

The virus is transmitted by midge bites and affects cows, goats, sheep and other camelids such as llamas. Midges are most active between April and November and not all susceptible animals show immediate signs of contracting the virus.

The impacts on susceptible animals vary greatly. Some show no symptoms at all but others can suffer productivity issues such as reduced milk yield. The most severe cases can be fatal for infected animals.

Clear reminder

Ms Middlemiss said: “This detection is an example of our robust disease surveillance procedures in action and it is also a clear reminder for farmers that the disease remains a threat, despite coming towards the end of the midge activity season.”

At the moment, Defra officials say there is no evidence the virus is circulating in the UK. But the disease has devastated farms in the Netherlands and strict rules govern livestock movements from affected regions.

Vets in the Netherlands have reported severe illness in sheep, with high fever and lesions around the coronary band, udder, face and mouth. Hundreds of farm businesses have seen animals culled.

UK farmers are reminded that animals imported from these regions must be accompanied by the relevant paperwork to clearly show they meet certain conditions designed to reduce disease risk, such as vaccination.

To report a suspected case of bluetongue, call 03000 200 301

What to look for

Symptoms of bluetongue vary. The main signs in sheep include mouth ulcers, drooling, lameness and the swelling of the head and neck. But infected cattle and goats often show little or no signs of the virus.

With potential for rapid  spread, the virus is transported by the wind dispersal of infected biting midges and through the import of affected animals, their germplasm – sperm and eggs – and foetuses.

Despite the onset of winter, livestock producers should remain vigilant for the disease in flocks and herds, says Sheep Veterinary Society president Joseph Henry, who chairs the Ruminant Health and Welfare bluetongue working group.

Reducing risk

“There continues to be no evidence of circulating virus in the UK midge population,” he says. “With the overall temperature continuing to drop, the risk of midge disease transmission is ever reducing.”

Legislation remains in place around any movement of animals into and out of control zones, adds Dr Henry. “It is still crucial for farmers to beware when buying animals in, take action to report any signs, and always, remain vigilant.”

When applying for a movement licence, farmers are urged to be as prepared as possible by planning and applying ahead of time to minimise any disruption or delay.

Farmers and vets can view the latest licences available and how to apply at ruminanthw.org.uk.