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Because this comes up time and time again.

Blood testing for CL is more than accurate than most HUMAN tests we use to diagnose (nurses on board here can verify the accuracy #'s, compare it to AIDS, etc)

FROM the UK -

How accurate is the blood test for CLA?
Validation of the ELISA for CLA indicates a test specificity of 99% and test sensitivity of
87%. This means that if 100 disease-free animals were tested, 99 of them would give a
negative CLA test result. If 100 animals with CLA disease were tested, 87 of them would
give a positive test result. In other words the test produces very few "false positive"
results and a moderate number of "false negative" results.
http://www.sac.ac.uk/mainrep/pdfs/clafaq.pdf

This doc explains the incubation period as well. Anyone remember math on statistics? You test your goat 2x a specific period of time apart. Add a third during the year to further counter and eliminate any false pos/negs.

You can also verify from UC Davis, WADDL, others the statistics on false pos/neg.

Now if you want to question a blood test, Johnes ELISA is one to question. It's dependability and cross reactivity issues put the ELISA at a level we would never consider using for human testing. Use AGID which is not as sensitive, but you won't be bald after double checking your tests and running fecals on all your false positives!

Andrea
 

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Nubian dairy goat breeder
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Is it worthwhile testing a single animal?

The sensitivity of the test and the possibility of false negative test results become more important when testing individual animals. There is a much greater chance of missing infection in a single animal than when a group of animals is tested. The CLA Monitoring scheme offers groups of sheep from which you can buy. Testing individual animal on a single occasion is therefore not equivalent to testing them as part of a group in the CLA Monitoring Scheme.


i think this is exactly why so many people think, testing is not worth the money. but obviously, buying from a herd that test regularly, give more security in buying a healthy animal.

this report does not talk about the risk for human health. what a pitty.
it might be rare that humans get infected but maybe it is more comon than we want to believe.
my hay farmer came yesterday night to bring me some hay. last summer he had a huge abscess on his lower chin. he told me that this was the second time he got this in a short period and he has no idea where it came from. i asked him if he had animals earlier in life and if he had seen it on his animals. he grew up with cows but could not remember seen it on them. then he said he helped on state fairs and had seen this on sheep. since his visit to a doctor was imminent, i told him he might want to have it tested for this disease.
i then forgot about this till yesterday night when i saw the scar on his face.
he told me he had to stay for a week in the hospital on i.v antibiotics. the abscess did not go away and did not change at all. it needed surgical removal and was tested positive for cl. they told him that this disease comes from horses. now, if human doctors don't know what they are dealing with, how can we know how many human cases there are??????
very scary
 

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With the launch
of a blood test for CLA it is now possible to detect animals with no external evidence of
infection "BUT" with internal lesions.
.................................

But....there is always a BUT or an opinon or a maybe in scientific papers..........BUT they do have to have lesions to test positive, so a goat or sheep who has CL, in the lymph glands, will not test positive if they don't have abscess, yet or again/rightnow.





Validation of the ELISA for CLA indicates a test specificity of 99% and test sensitivity of
87%. This means that if 100 disease-free animals were tested, 99 of them would give a
negative CLA test result. If 100 animals with CLA disease were tested, 87 of them would
give a positive test result. In other words the test produces very few "false positive"
results and a moderate number of "false negative" results.
...............

How does this help you or I purchasing a goat and testing it. It sounds wonderful that a test is 87% accurate...99% accurate with abscess material....unless the goat you are purchasing doesn't have an abscess and tests negative, which most stock living in the family farms have few to no abscess after the intial ones (It's the 'cure' folks talk about on the holistic forums)....but sorry 87 goats negative out of the 100 tested is NOT doing me any good.

The only way for sure is to know who you buy from and to test the exude from the abscess.

I do applaud the program they are running, very much like what the USA needs to do with CAE and CL also. But you have to know what Elissa testing gives you for both Johnnes and CL and what AGID does, and what PCR does and what CHI does. But it is a nice read, just doesn't bolster quite well enough the point you think you are making.

So my advice still stands. Johnnes and CL...TB and Brucilosis are wastes of money testing unless you have abscess for CL or at least send to UC Davis for their CHI bloodtest for CL....for 99.9% of the folks on this forum. The rest is marketing for websites. Vicki
 

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if a goat only test positive if there is an actual abscess going on, how comes a vaccinated goat (should not have an abscess) can and most likely will test positive?
 

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I agree, vaccinated animals do not get an abscess (unless, of course, they were vaccinated after getting the disease which means the vaccine was used incorrectly anyways)... that makes no sense. I was pretty sure they could test truly positive without having an abscess somewhere. Just like with the shot, antibodies are produced and circulated in the bloodstream so it's readily available to attack a new infection, be it in the same area as the last or in a different area - internal or otherwise. The tests look for antibodies, and that's why vaccinated animals test positive. Once an antibody is produced it simply floats about until it 'falls apart' naturally or destroys the disease it's made for, but more are always made. Which is why people can't get the exact strain of the cold over and over again - we begin making antibodies continually after initial infection, and once we 'defeat' it, they're still there, waiting to destroy it again if we get reinfected with the same one. Once we encounter a new strain of cold, or flu, etc, that we've never battled before or been vaccinated against is when we often get sick - same with animals.
 

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Because a shot/vaccination goes from IM or subq right into the blood stream. CL is in the lymph glands, unless it is in the bloodstream going to make (symplisiticly here) an abscess why would the goat test positive on a blood test? Even a walled off abcess that is ready to burst, why would a blood test be positive if the bacteria is then in the abscess only?

What they have you thinking with this is that this is a blood born 'disease' like CAE. When in fact this is like the herpes virus in humans, which a blood test rarely catches, although it is harbored in the body for life. Only a skin scarping of the lession will give you positive results 99% of the time.
Vicki
 

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now, if shots given sub.q, and most vaccines do, it does not go directly in the blood stream but in the lymphatic system. it then goes in the lymph nodes where the t-cells are produced that memorizes pathogens. if the body gets attacked from a certain strain of virus or bacteria, those t-cells get activated and trigger a production of cells that destroy the bacteria or virus.
the whole process is a lot more complicated as i wrote it but should give a general idea. ;)

that is why it does not make sense to me that only active cases should show on tests.

only i.v. goes directly in the blood stream. ;)
 

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So a shot subq or im, just floats along from the shot site on what...spit? Nonesense. Anything given IM or subq is taken by the blood sure not right away like giving something IV, into the surrounding tissues, organs etc. Even things given orally are absorbed by the mucous membranes in the mouth and go into the blood stream.

Where are T cells? Vicki
 

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I had a doe- a whole 'nuther story on how she came to me and was CL pos. (Yes, it was from an ADGA judge.)- who developed a lump up high in her rear udder when she was isolated before CAE testing etc. She came back suspicious for CAE from WADDL, so I did a hands on and found the lump.

Took her straight to the vet who did a lumpectony in his office- totally encapsulated tissue with pus inside. Sent to the Kord Lab in Nashville TN where they cultured a HOT CL. She stayed in isolation up to kidding- kids were pulled, she never saw them- and then at TB/Bruc. testing some 6 months later, vet pulled blood to send off to UC Davis for CL.

Guess what? She was negative for CL by UC Davis blood test. And she never had another lump or sick day in her life. This is why I do not trust blood testing for CL. Taking NO chances.
 

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Betsy, your story is mirrored in most of the stories I have had here and know peronally from other farms. I bet if you had sold her she would have had either an internal or another external abscess come up.

Now saying that I do know the CHI test is alot more accurate and perhaps testing via UC Davis this last several years it would have been picked up. But I have had also a doe who had positive abcess removed whole, most after kidding, who tested negative for cornybacterium p.

Most herds reputation proceeds them, CL is simply not anymore the problem it used to be when you do your homework. Not alot of herds who show can have CL and keep goats home when abscess is found at the spring shave, at least not in dairy goats. Way to small of world. Vicki
 

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Because a shot/vaccination goes from IM or subq right into the blood stream.

this is plain not true. it first goes in the lymphatic system and in the lymphnodes before it can make antibodies and be detected in the blood.

vicki here is a very nice site for you to read up about antibody and how it works. very easy written and for class room use ;)

http://www.cellsalive.com/antibody.htm
 

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I wish I could add some useful information to this conversation but I can't. Just when I think I researched & understand a disease & I'm doing the right thing, I read that I could be doing something more (or different, or maybe not at all?). I've always known CLA blood testing was not 100%. I've always known that testing the excudus from a lump was 100%.

We've been testing for CLA for 4 years now. We've never had a lump (except cd/t reaction lumps until we switched brands). We've used 3 different labs at various times, for diversity, clarification, vet preference, cost, whatever reason.

So, am I reading correctly that I should stop testing, because it is not accurate & proves nothing? Isn't it better than NOT testing at all? If I don't test, how am I to show that we are aware of CLA, and are doing our part to keep a clean herd?

I DO understand that testing results can only represent a percentage of accuracies, and also that the results are a representation of the day status as of the day the blood was pulled. I am certianly not one to advocate a "disease free herd", as I don't beleive any farm can make that claim, I would prefer one to advertise tested free of disease as of ??/??/2009, and biosecurity practices have been implemented.

So how does one go about supplying a negative status to their customers in a meaninful way? Particularly when you don't have 25 years experience in goats and a fantastic reputation as of yet? I'd love for this thread to be opened up to include buyers thoughts, what they look for, how they choose a reputable breeder(based on disease status), etc ect.

Geez, maybe I'm tired & not reading or typing correctly, if so somebody set me straight!
HF
 

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I would like to see the references used to achieve the conclusions drawn in the obvioulsy "geared towards consumer" paper in the link posted by the op. much can be revealed by reading the study that is used to make conclusions. it very well could state the answer to the debate but they could have ultierior motives for attempting to cover it. for isntance they may be trying to recruit people into the program.....hmmmm a gooberment would never knowingly leave important info out of publications meant for the general public now would they? they probably figured it would be over our heads......us silly little uneducated small stock producers.

it is my understanding that one of the whole problems with cl is that it can hide in the lymphatic system and evade destruction. hide is the key word.
 

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If you want to know a useless test, look to the mycoplasma tests. Johne's is probably right up there with it, but again, it adds weight to a trusted herd that tests ALL of the animals regularly. I don't ever rely on a single negative test, especially if it's on a single animal within the herd (or even a small, select group).

CL - I read that one of the concerns with this is that the abscesses are often internal and therefore hidden from normal view. Is this not thought to be the case anymore?

I still do not buy that there is no lateral transfer of these diseases. I am paranoid enough to think that *any* bodily fluid, if enough of it is present for exposure, is able to transmit and therefore I don't take the chance. JMO. (But if we want to discuss lateral transfer again, we should bring up the archives and then start a new thread rather than let this one drift so far.)
 

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Happy Farmer, not much has really changed with CL over the years. Other than we now know what it is :) Your best bet is always to purchase from established herds. This is a non issue in most meat goat herds in my state, or nanny and billy type herds, they deal with the abscess, slice an dice or inject with formalin. Vaccination is not 100%, by any means, but it placates buyers until they get better information. Vaccination or keeping CL in dairy herds will kill your sales. It's really the only reason why it is such a non issue in most dairy goats, hit us in the pocketbook and we will clean up our acts. CAE is so much more the hidden disease, I soo hoped with the internet we could have come so much further than we have.

Yes test, just know what the results even mean with the type of test the place runs. Know that a negative test for CL on blood is not the whole answer. In purchasing new stock quaranteen is paramont because they WILL get an abscess during that period, that you then can test and cull or keep the goat. Vicki
 

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Vicki - why do you say a goat "WILL" get an abscess during a quarantine period? Aren't many CL+ goats asymptomatic for long periods or perhaps having only internal abscesses? How long of a quarantine period are you practicing/advising?

We quarantine here but we also only buy from trusted, whole-herd tested stock with a long history of negative test results. To date, we've only purchased from only two herds but we are looking to broaden the base and have made serious inquiries with others. When we buy from out-of-state, we will have an extended quarantine, even if the seller's herd meets all our requirements.
 

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I have never had a goat not get an abscess during 90 day quaranteen if they had CL. Between the stress of the move and the stress of quaranteen you will see abscess. Yes I do know there are internal abscess, but during periods of stress goats will have external ones. It's the most efficient way for the bacteria to get out of the body in large enough numbers to be infective and to repeat it's lifecycle. Stress always triggers abscess development. Vicki
 
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