Bluetongue illness is a noncontagious, insect-borne viral disease that affects ruminants, most notably sheep, but also cattle, yaks, goats, buffalo, deer, dromedaries, and antelope. High fever, profuse salivation, swelling of the cheeks and tongue, and cyanosis of the tongue are all major symptoms. Swelling of the lips and tongue gives the tongue its characteristic blue look, albeit this symptom is only seen in a small percentage of the animals. Nasal symptoms such as nasal discharge and stertorous breathing may be present. Some animals acquire foot lesions, beginning with coronitis and leading to lameness. This can result in knee-walking in sheep. Neck torsion is seen in seriously injured animals. Hosts are typically infected by the saliva of a biting midge. The virus distributes locally and replicates in regional lymph nodes, resulting in viremia and systemic spread. Virus replication in hematopoietic cells and endothelial cells causes endothelial damage, bleeding, vascular occlusion, tissue edoema, and epithelial sloughing owing to microvasculature loss. Sheep eat less because their jaws hurt, and they will hold food in their mouths to soften before eating. They may champ, resulting in a frothy oral discharge from the corners of the lips. Small haemorrhages can be seen on the mucous membranes of the nose and mouth when examined closely.