CL — you can prevent it, treat it or you can cull it

Recently I had a call from a concerned producer about a goat they had purchased. This goat had developed a cyst in a lymph node as she neared her due date and now they had raised concerns of a possible Caseous lymphadenitis (CL) infection. As producers, CL can be a dirty word. We know the disease is out there but we try not to discuss it. So what is CL and why should we care about it? Caseous lymphadenitis is a chronic and highly contagious dis- ease primarily of goats and sheep caused by the bacterium Coryne- bacterium Pseudotuberculosis. CL is a serious zoonotic infection that will lead to economic losses for the producer through condem- nation or trim of infected carcasses or their hides, loss of sales for breeding animals and increased death loss and cull rates. It is found worldwide and is characterized by the formation of abscesses in or near lymph nodes or even inside the body on organs and internal lymph nodes. (As we discuss CL it is worth noting the external form is considerably more common than the internal form in goats.)

Corynebacterium Pseudotuberculosis is a bacterium that is very hardy and can survive harsh environmental conditions, making eradication following introduction difficult. Once the bacterium is introduced to a farm it remains on the property primarily through


contamination of the environment from active draining lesions. The presence of moisture, organic material or shade can assist in the bacteria’s survival in an area. This, unfortunately, makes ex- posure of other goats much easier. Any goat exposed to the bacteria can develop infection but the incubation period is variable (1-3 months) making it hard to identify where the exposure may have occurred.

Following exposure and the incubation period, affected animals will start to develop encapsulated abscesses. These abscesses, left untreated, will ultimately burst, sending the bacteria contained within into the environment and exposing additional livestock. So how can producers manage or prevent such a disease? There

are three different effective approaches: prevention, treatment and culling.

Prevention Preventative measures are always valuable even if a herd has

a known issue. • Blood Testing. Each producer should start with blood testing all new animals prior to purchase. Doing so can help prevent the purchase of CL positive animals and substantially reduce the risks

September 2020 | Goat Rancher


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