Bluetongue is a viral disease that primarily affects sheep, but it can also infect other ruminants like cattle and goats. The disease is caused by the Bluetongue virus, which is transmitted by biting midges, particularly those in the Culicoides genus. Symptoms include fever, swelling of the face and tongue, and lameness. The disease is not contagious between animals but can spread through insect bites. Bluetongue is prevalent in warm climates and can lead to significant economic losses in the livestock industry. Vaccines are available to help control outbreaks and protect affected animals.