OCCURRENCE – CL occurs in sheep across the U.S. The infective bacteria reside in the environment and on the skin of sheep. Wounds caused by shearing, thorns, splinters, grass awns, etc. are invaded by the bacteria which then find their way to regional lymph nodes in the body. There, they form boils, or abscesses, that become walled off by scar tissue. Infective bacteria may escape from the boils and spread the infection to other parts of the body. It would appear that the causative bacteria may be introduced into clean flocks by the way of carrier animals since all flocks are not troubled with this disease. Once introduced into the flock the disease oftentimes affects a relatively high percentage of susceptible animals. CL is very likely spread by environmental contamination from ruptured or lanced boils by injection, and at shearing.

SYMPTOMS – CL is manifested in two forms; 1); external abscesses in superficial lymph nodes and 2); internal abscesses. Both forms may occur simultaneously and frequently causes gradual emaciation and eventual death. Sheep experiencing only external abscesses may show no other symptoms and heal spontaneously.

TREATMENT – Antibiotics have been of little value in treating CL. The infective bacteria, walled off inside abscesses, are inaccessible to blood carrying antibiotics. Surgical drainage of abscess must be performed so as to avoid contamination of the environment with the contents of the abscess. It has been recommended that a large gauge needle be inserted into the abscess, some of the pus withdrawn into the syringe, and formalin injected into the abscess from a second syringe. After allowing several minutes for the formalin to sterlize the contents of the lesion, the abscess is lanced,mcarefully collecting the drainage in a receptacle. Another recommendation calls for surgical removal of the entire abscess intact.