# Question: Texas Vet Labs CL Vaccine?



## Dairyfarmer (Mar 11, 2014)

Texas Vet Labs introduced their vaccine against CL in spring of 2012 and we are now approaching the two year mark. I am curious if anyone here has used the Texas Vet Labs Vaccine and can share their experiences and observations.
Thanks.


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## KJFarm (Oct 26, 2007)

If you are dealing with abscesses in your herd, the best vaccine will be an Autogenous Bacterin made from the exude of an abscess from your animals. 25-30 years ago when we had a problem, we had it made for our herd, and it worked better than the OTC ones did. It costs more to have it made, but at least you know you are vaccinating against the strain that you have on your property.


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## Dairyfarmer (Mar 11, 2014)

Understood.

But my question was specifically in regard to experiences or observations using the Texas Vet Labs vaccine.


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## KJFarm (Oct 26, 2007)

So, my answer is, NO, do not have any knowledge about the vaccine, nor do I know of anyone who has used it. Those of us who have been in goats for decades, choose to eradicate CL by strict culling of exposed or affected animals.

If you vaccinate with the CL vaccine, you will get false positives on tests for CL. Seems like you would be "shooting yourself in the foot" by vaccinating, unless you have an ongoing problem. JMHO


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## Dairyfarmer (Mar 11, 2014)

Thank you. I appreciate your reply. I have been one of those lurkers for a long time and recently thought I would participate. My query , and most recent reply, was not designed to offend

Please understand we have zero tolerance for CL (and CAE) and cull. Our herd is closed, we never show (or ever have), and we operate under a strict Biosecurity program.  

Aside from the issue of a positive blood test for CL if a vaccine is administered; there is an addition component being suggested for an integrated program to eradicate the disease in infected herds. That is to suppress abscess development that could further spread infection, coupled with hyper vigilance and zero tolerance (culling). 

Thus, the efficacy of a vaccine becomes important-if-this particular strategy has any merit or deserves any serious consideration. 

I am still curious if any others have actually used a commercial CL vaccine and what their experience has been. I'm just asking.


Ron


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## doublebowgoats (Mar 6, 2008)

I don't know of anyone who uses any kind of CL vaccine. There is such a stigma with it because it is assumed if you use it, it is because your herd has or has had CL. Do you have any experience with vaccine, Ron? I just recently heard of the thing through WSU that suppresses abscesses in positive animals.


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## Dairyfarmer (Mar 11, 2014)

Thanks, we have had no experience with the vaccine. Our vet who specializes in small ruminants and infectious disease is following the vet med literature and talking with his colleagues. There is a stigma to CL that unfortunately prevents coping with the disease on a herd, state or national scale. The same is true for widespread denial of anecdotal and strong scientific evidence (mostly European) regarding the extent of horizontal transmission of CAE.
Stigma and denial are real problems preventing the development of the goat industry (meat and dairy) in the US (and other countries.) Description of losses to CL and especially CAE in some European literature approach 60%


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## swgoats (May 21, 2010)

My concern with vaccinating is that if the goat will there after be test positive, then there is a risk that future buyers/owners could cull it due to a test result. I'd love to think all the goats I sell go to forever homes, but I know they do not. Even I sometimes purchase a goat and turn around and sell it after a couple years if I must cut herd size. Personally I think it would be better if a vaccine works, for us all to use it, but as long as there are people testing and using those results to cull, I don't see how we can.


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## [email protected] (Sep 18, 2008)

Someone posted on FB that there is a test being worked on that would test for actual CL rather than the antibodies. Like the PRC test for CAE. So if you knew a goat had been vaccinated, you could still test for the disease. 

I have no experience with the vaccine.


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## Dairyfarmer (Mar 11, 2014)

The only PCR based assay I know of is being developed to identify the bacterium as isolated from an abscess. There are no circulating bacteria as there are antibodies and thus a general blood test based on DNA analysis would not work. (In a previous life I headed a lab that developed and ran PCR, ELIZA and other assays).

However-a cost effective-reliable-PCR test on an isolated sample could help by cutting down the testing time. Right now the lab that does our testing-has a turn around time of 9-14 days. Usually 14, if a goat has a CL abscess it can progress to bursting well before a test result comes back. Because the bacterium is so highly infectious often it is assumed that an abscess in or near a lymph node is diagnostic for CL in a herd with a history of the disease. The animal is then culled.

The blood test for CL is often not reliable for an individual animal. Circulating antibody only indicates exposure to the bacteria, it does not mean the animal is actually infected. In control strategies, the assay is used to assume an animal has come farm where the organism is present.


Thanks,

Ron


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## doublebowgoats (Mar 6, 2008)

I was told recently that a positive blood test would indicate that at any point in the future this animal could develop an abscess. So basically exposure=disease. It was confusing to me. I know with CAE that DNA based test eliminates any doubt if an animal is infected, but there is no such blood test for CL? I actually know very few folks that do blood tests for CL because of the confusion


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## Dairyfarmer (Mar 11, 2014)

We now always ask for CAE testing results, and have met some really wonderful breeders who readily supply that information. We have one situation that is quite unusual. We were planning to purchase two very nice breeding bucks. Previous CAE ELIZA antibody tests had been negative. The breeder decided to have the next round of tests based on PCR. The PCR tests were positive.

We know that the lentivirus is a retrovirus that integrates into the host's genomic DNA. The PCR assay will identify such integrated DNA. Our thoughts are that an animal could become infected early on, produce some level of antibody to the virus, the virus could integrate and the titer of antibody diminish over time. Since these were older bucks maybe that happened. The PCR assay indicates the integration of viral DNA into the host genome-it does not necessarilynindicate that intact virus integrated-but that was enough for the breeder and us to say these really beautiful breeding bucks were CAE+.

As for the CL test-it just means antibody was raised after exposure to the bacterium, and in general used to indicate the bacterium is present in a herd-or the animal was exposed. It does not necessarily indicate active infection. If we purchase adult goats again, we would request tests for CAE and CL, having had animals erupt in CL abscesses after quarantine.


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