Blue tongue is a virus disease that occurs in sheep, but also with goats and cattle. The disease is spread by the Knut, a mosquito that feeds on the blood of horseshoes. The insect is good in the vicinity of ditches or damp meadows. The mosquitoes become active when the weather gets warmer.
The disease is often deadly for sheep. Cows, goats and other ruminants usually have fewer serious symptoms. They can pass on the virus to other animals. People cannot get infected with the blue tongue virus.
Animals that are very sick get a blue tongue. Other symptoms include high fever, a lot of drooling, a swelling of the head, inflammation of the hooves and lame. Sheep who survive the disease can still suffer from the consequences their entire lives.