Caseous Lymphadenitis (CL)

Producers do not like to talk about this common goat disease.  If you raise goats long enough, you will eventually have to deal with CL.  In my opinion, any goat disease that can be prevented by a simple vaccination is a much better alternative than treating or culling infected goats.

We are extremely cautious when purchasing new goats.  I ask a lot of questions and prefer to purchase from producers that have a vaccination program, or at the very least a CL management program already in place.  If a producer tells me he/she never has had any throws a red flag.  Goats get lumps from bacterial infections, injury,  etc.....not necessarily CL lumps.  Either they have not been raising goats for a very long period of time or they are simply not being truthful.  

We do not recommend the blood test for CL as a determination of individual exposure to or active infection of CL. The blood test is highly inaccurate at best.  I have known many producers who have blood tested goats, getting NEGATIVE results, only to have them pop a CL positive lump shortly thereafter.  Adversely, I have had 2 different producers purchase mature does that I had vaccinated multiple times for CL.  They blood tested them & the test came back negative....not picking up the presence of antibodies produced in response to the vaccine as it should have.  There is value in herd wide blood testing for CL to determine prevalence of infection within a herd. 

Washington State University ~ CL explains what I am referring to when answering: "What tests are available for CL?"

"There are two testing methods for CL offered at WADDL: bacterial culture to detect the bacterial organism in abscess material, and serology to detect C. pseudotuberculosis-specific antibodies in sheep and goat blood samples. For animals with visible subcutaneous abscesses, it is best to submit abscess material for culture since this is the most direct and definitive method to diagnose CL in an individual animal. It is recommended that all abscesses be cultured regardless of serology test results.

The serological test is the best method of “herd-level diagnosis” (screening herds).  WADDL runs the Synergistic Hemolysin Inhibition (SHI) test, which measures the antibody response to an exotoxin produced by the organism. No CL serological test is sufficiently reliable to confidently detect infection in individual sheep or goats, therefore the serology results for an individual animal test should be interpreted with caution. Furthermore, although a positive serologic test result alone may indicate active infection, it also may indicate past infection that has resolved.  The SHI test specificity and sensitivity for individual animals may not be high in some herds, however, the prevalence of positive tests within a herd usually reflects the herd prevalence of infection reasonably well."

We VACCINATE.  It is NO sales gimmick. We have been vaccinating our entire herd for CL, including any goats purchased and added to our herd, since July of 2007.   Additionally, we have a vet collect a sample from any lump that shows up on our goats and send it away for biopsy and identification.  This has been done on a regular basis, since June of 2011.  Yes........goats get lumps, that does not mean they are CL lumps.  The ONLY way to tell for sure is to biopsy them.  All biopsies done on our own stock from that time frame forward have tested NEGATIVE for CL.  

The article below was written by Sara Beth Routh @ the NC Cooperative Extension.  It is informative and worthwhile reading!