State vets are stepping up vigilance to prevent bluetongue disease crossing the Channel as midge activity reaches its summer peak.

The possibility of infected midges blowing across from the Continent to the south-east of England is seen as the likeliest source of bluetongue in the UK.

There have been confirmed cases in Netherlands (474), Belgium (695), Luxembourg (8), Germany (857) and France (17), but vets are encouraged that recent alerts in Germany and France have proved negative which suggests the disease has not survived the winter.

“Midges need to have fed on the blood of an infected animal before they can spread the disease,” Scotland’s chief veterinary officer Charles Milne, told journalists at a briefing in Edinburgh.

“We know cold weather usually puts a stop to the spread of bluetongue but we have to be aware of the risks.

“We are now reaching the peak activity period for these midges in late May and early June. There are 16 surveillance sites in the UK, mostly in England, but obviously if there is any incidence that would be stepped up considerably.”

Meteorological experts have told vets that there are only 100 hours each month when the weather might make it possible for the midges to cross the Channel.

Mr Milne is also advising farmers to avoid importing livestock from infected areas. All animals coming into the country have to be blood tested and so far all 3017 tests have proved negative.

Should the disease reach the UK, a protection zone of at least 100km would be declared around the infected area, with a 20km zone within it, plus a further 50kg surveillance area.

Restrictions on the movement of animals, carcases, semen and ova moving out of each of the three zones would be put in place and additional housing requirements and measures to control midges with insecticides may also be required within the 20km zone.

Widespread slaughter will not be used to control bluetongue but any imported animals or other small groups of animals shown to be infected could be slaughtered to prevent spread.

Compensation will not be paid on animals infected before being imported into the UK but compensation at market value may be paid for other animals compulsorily slaughtered as a part of disease control.

DEFRA has more about bluetongue and government policy on its website.