Caseous lymphadenitis (CLA) is a contagious disease of sheep and goats, caused by an infection with Corynebacterium pseudotuberculosis. In sheep the infection commonly manifests as abscessation of the lymph nodes, following entering through skin lesions. A survey in 2001 found that 18% of terminal sire breed flocks in the UK were infected. In the UK, the most common lymph nodes are the parotid and submandibular. Abscessation of these superficial lymph nodes is usually quite easily recognised, particularly in shorn sheep.