Rachel Hebditch

Bluetongue cases have slowed with the onset of winter and there is some hope that animals will be permitted to move out of the restricted zones to live during a ?seasonally vector free period?. This would be between January and March as this corresponds directly to a period of low midge activity when midges are either dying off, inactive and/or unable to transmit virus.

Bluetongue is a viral disease of ruminants spread by a biting midge that is thought to have reached the UK from Europe in August 2007.

DEFRA issued a tender to supply between 10 and 20 million doses of Bluetongue BTV-8 vaccine in November 2007 and it is hoped that vaccine will be available by the summer. In the government?s Disease Control Policy Statement they say: ?In keeping with the principles set out in the Bluetongue Control Strategy, which was developed in partnership with the farming industry, livestock keepers will be offered the opportunity to purchase vaccine from the bank. We are developing a detailed plan with representatives of the farming industry, Bluetongue scientific experts and others as to how a vaccination programme would work.?

There have also been discussions as to whether expanding the Surveillance Zone to the whole of England so that more animal movements would be permitted inside that zone would be of economic benefit. The assumption is that movement restrictions would be in place for a full twelve months.

The bluetongue virus appeared in Germany, Benelux and France in 2006 and has inexorably spread with large areas of France now being in a restricted zone. However the five alpacas reported to have died of bluetongue in Belgium turned out, on post mortem, to be free of the disease.

In December, the Veterinary Record carried a report on the death of an alpaca from bluetongue in central Germany from veterinarians M. Henrich M. Reinacher and H.P. Hamann. Three months before its death the alpaca gave birth to a healthy cria. Four weeks before it died, the alpaca showed signs of colic with recumbancy and tympanic abdomen. The animal was degassed via nasogastric intubation and recovered quickly but the cause of the clinical signs remained undetected. Immediately before the infection both mother and cria were in excellent body condition and both showed no sign of an underlying disease.

Acute clinical signs started with ?hiccup-like? breathing and a stertorous sound discernable by auscultation. One hour later the animal was inappetant, recumbent and lethargic. Seven hours later the animal was observed coughing and mildly disorientated. Fourteen hours after the first observation of signs, the animal died.

Sequences of bluetongue virus were found in tissue samples of the blood, lymph nodes and spleen. The rest of the herd, including the cria, remain healthy.