The response of sheep to bluetongue virus infection ranges from inapparent to acute and fulminating disease. About two days after the rise in temperature there is a mucopurulent, often blood-stained nasal discharge and frothy saliva.
Necrotic ulcers develop on the tongue and corners of the mouth.
Respiration is increased. Diarrhea and dysentery may occur. In some animals, there may be foot lesions, lameness, wry neck, severe conjunctivitis, and facial swelling. Sheep in Canada are considered to be free of the virus. Parsonson, I. M. 1990.