Caseous lymphadenitis in small ruminants.

Caseous lymphadenitis is a contagious bacterial disease that affects sheep and goats. It is characterized by abscess formation in the skin, internal and external lymph nodes, and internal organs. The causative agent is Corynebacterium pseudotuberculosis. The disease can become endemic in a herd or flock and is difficult to eradicate by virtue of its poor response to therapeutics, its ability to persist in the environment, and the limitations in detecting subclinically affected animals. The disease causes significant economic impact on the small ruminant industry through decreased meat yield, damaged wool and leather, decreased reproductive efficiency, culling of affected animals, and mortality from the internal environment.