What is bluetongue?
Bluetongue is an insect-transmitted, viral disease of domestic and wild ruminants. At present 24 serotypes of the virus are recognised. The serotype introduced into northern Europe in autumn 2007 is serotype 8 which only occurred previously in countries in regions of Africa and Asia. There are six serotypes present in different regions of Europe. These are BTV serotypes 1,2,4,8,9,16. (Bluetongue map of Europe)
What are the possible signs of bluetongue disease?
The signs of bluetongue disease can be similar to those of other diseases so it is important that you notify your vet if you suspect bluetongue disease in order that a diagnosis can be made.
 | Sheep: The signs in sheep are very diverse. Some sheep become seriously ill and die, while others may exhibit hardly any signs at all. In most cases the first sign is high fever, followed by swelling and pain in and around the mouth, which in turn causes excessive salivation. Ulcers appear on the inside of the cheeks and the sides of the tongue; the oral tissue becomes a reddish-purple colour and the tongue can turn blue – hence the name bluetongue. Some sheep may develop swollen heads. Lameness, weight loss, breathing difficulties, and discharges from the nostrils and eyes are other possible signs. Mortality can exceed 25%. |
 | Cattle: The signs in cattle are usually less severe than in sheep and in some cases animals may not show clinical signs of the disease. Signs may include discharges from the nostrils and eyes, profuse salivation and sores on the teats. Productivity and reproduction can be severely impacted. |
 | Goats: The signs in goats are generally similar to those in cattle. Again, they may show no clinical signs of disease despite being infected with the virus. |
 | Other ruminants: Camels, buffalos, deer and other wild ruminants can also become infected and they generally display only mild signs of the disease. |
from Derksen, D. and Lewis, C. (2007) Bluetongue virus serotype 8 in sheep and cattle: a clinical update. In Practice 29, 314-318. http://www.bvapublications.com © British Veterinary Association
Is bluetongue contagious?
Bluetongue is not contagious as ruminants cannot directly infect one another. It is transmitted by a very small insect (midge - Culicoides species), which passes the virus by biting uninfected animals after biting infected animals. In infected pregnant animals, infection can spread vertically to the embryo or foetus via the placenta.
Does bluetongue pose any threat to public health or food safety?
Bluetongue does not affect humans, nor is there any risk of the disease being contracted or spread through meat or milk.