CSU ext

Caseous lymphadenitis is a chronic, debilitating disease of sheep and goats characterized by abscesses caused by the bacterium Corynebacterium pseudotuberculosis.

How is it transmitted? The bacteria usually enters through skin wounds such as those produced at shearing, or through the mucous membranes of the mouth and respiratory system. Sheep and goats with abscesses that are discharging pus are a prime means of contaminating the animal’s environment and spreading the disease. The disease is most often introduced into a flock by entry of an apparently healthy carrier from an infected flock. Contaminated shearing equipment, halters, feed bunks, stalls help spread the infection. Infection occasionally occurs in cattle, pigs and other animals exposed to the infective pus from abscesses.

abcess on shoulder
Abcess caused by shearing wound

What are the signs in sheep and goats? Painless abscesses of the lymph nodes of the head, neck, and other regional lymph nodes are typical. Older animals more often show signs because of the chronic nature of the disease. Some sheep and goats may only have internal abscesses and usually present with chronic weight loss and emaciation.  At post mortem examination characteristic abscesses with cheesey, white pus are often found in the liver and lungs.

Abcess on jaw
Abcess in goat
More information at Merck Vet Manual: