Bluetongue - advice and guidance
|Bluetongue case in a clinically affected Highland cow.
Extensive superficial erosion of the muzzle with a mucopurulent nasal discharge
Bluetongue is a viral infection of ruminants that until recently was not seen in Northern Europe or Great Britain. There are 24 serotypes of Bluetongue and different serotypes have different geographical spread. There appears to be no cross immunity afforded following infection from 1 serotype to the other serotypes. Bluetongue is spread via some species of midges; the geographic distribution of these species of midges is changing as a result of increased temperatures and humidity. In the summer of 2006 Bluetongue serotype 8, BTV8, infection was observed in Northern Europe causing limited number of outbreaks and relatively little impact. Last year there were large numbers of holdings affected in Northern Europe and a small number of infected animals seen in Great Britain. It would be likely therefore that we would have a similar increase in the number of infected animals in Great Britain this year. Further animals have been found as part of the pre-movement blood testing regime, case in Poole.
The only effective way to try and prevent this rapid escalation of Bluetongue cases is via a vaccination program, a vaccine for BTV8 will be hopefully be available later this year. DEFRA have decided not to make this compulsory, but are advising farmers and livestock owners to vaccinate their stock. It has been estimated that if approximately 80% of susceptible livestock are vaccinated then we should be able to prevent a major Bluetongue outbreak. Cattle will require to be given 2 doses of vaccine whereas sheep will only require a single dose, it is hoped that the vaccine will be available in the next couple of months. Initially stocks will go to vaccinate animals in the protection zone and then in the surveillance zone. Actual costs of the vaccine are unknown as yet but are hoped to be less than £1 per dose, livestock owners will be able to administer to their own livestock with the vaccine only being available from veterinary surgeons. Animals will need to have booster vaccines given for the following 2 years to give good long term immunity.
Contact your vet now and pre-order what you need for sheep, cattle and goats
Until vaccines are available the only other control method is prevention of biting from midges, in sheep this could mean a delay in shearing as shorn sheep seem to be bitten more readily, housing of livestock when midges are most active, avoidance of fields where midges are most prevalent or the use of insecticidal products to try and prevent exposure to the midges.
The final concern is that other serotypes could move into Northern Europe and pose further threats to British livestock and we can only hope that if this appears likely that newer vaccines become available that give greater cross protection.
For pictures of Bluetongue please look at the following links.
A question and Answer document on Bluetongue by the Rare Breed Survival Trust
Try this link for images of sheep and cattle and also for some things that are not Bluetongue (this is a large pdf file - please be patient)
And for cattle
Steve Grills March 2008