Livestock farmers in high-risk areas of East Anglia have been urged to stay vigilant amid a "very high probability" of bluetongue virus outbreaks this summer.

Dozens of Norfolk cattle and sheep were found to be infected with the potentially-fatal animal disease during the winter.

But Defra says although there are "currently no live cases", the warmer summer weather means there is a "very high probability of a new introduction of bluetongue virus serotype 3 (BTV-3)" this year, carried by infected biting midges being blown over from northern Europe. 

Farms near the east coast from Norfolk to Kent are among those considered at highest risk of incursion.

Defra has introduced free bluetongue testing in the highest-risk counties of Norfolk, Suffolk, Essex, Kent and East Sussex, to prevent animal movements potentially transporting undetected diseases to new areas.

It is part of a Defra's disease control framework, published last month, which sets out how the government will work with the farming industry to manage any bluetongue outbreaks.

Christine Middlemiss is the UK's chief veterinary officerChristine Middlemiss is the UK's chief veterinary officer (Image: Defra)

Meanwhile, UK chief veterinary officer Christine Middlemiss said farmers should monitor their animals frequently for clinical signs, and make sure they are registered with the Animal and Plant Health Agency (APHA) so they can be quickly located in the event of an outbreak. 

“Bluetongue does not pose a threat to human health or food safety, but the disease can impact livestock farms, and cause productivity issues," she said. 

“We know that the likelihood of bluetongue virus entering Great Britain is increasing and so I would urge farmers to remain vigilant and report any suspicions to the APHA. 

“If you intend to move animals to live out of high-risk counties please take advantage of this free testing as it will help stop the movement of undetected disease.” 

The free testing is also available for animals being sold at a market within a high-risk county where there will be buyers from outside the high-risk counties.

The disease control framework confirms that, upon first detection of disease in England, 20km movement control zones will likely be established to prevent the movement of potentially infected animals to new locations. Movement of animals within zones, or to slaughter, will be permitted. 

If there appears to be "limited local spread", bluetongue control zones will be put in place alongside limited culling of infected animals to contain and eradicate disease. Keepers will be compensated the market value for any animals culled.

The government is also "actively engaging with vaccine manufacturers and industry" to gain access to a "safe and effective" BTV-3 vaccine as soon as possible, but adds it is vital that any vaccine has the confidence of industry, consumers and trading partners.  

Bluetongue virus is primarily transmitted by biting midges and affects ruminants including cattle, sheep, goats and deer, as well as camelids such as llamas and alpacas.

Bluetongue does not affect human health or food safety, but it is a notifiable disease and suspected cases must be reported to the APHA on 03000 200 301.