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Thread: What is known to 'mess up' TB tests

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    What is known to 'mess up' TB tests

    On another thread there is reference to the johnes vaccine interfering with the bTB test - what else may possibly interfere? Perhaps these are well documented - but I don't know what may - I know it is recommended to treat cows on the reading day, but I have not seen it that you cannot treat with anything on the testing day?

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    Re: What is known to 'mess up' TB tests

    I believe if you vaccinate for johns disease it will throw up false reactors for TB in much the same way that if you do a johns test too soon after a TB test you will get a lot of false positives for johns.

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    Senior Member greysides's Avatar
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    Re: What is known to 'mess up' TB tests

    Treating an animal with a drug with a withholding time on the injection day is best avoided.............just in case.
    History is a race between education and catastrophe.H. G. Wells.

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    Re: What is known to 'mess up' TB tests

    Quote Originally Posted by greysides View Post
    Treating an animal with a drug with a withholding time on the injection day is best avoided.............just in case.
    Not to mention strictly forbidden according to DARD

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    Re: What is known to 'mess up' TB tests

    Is it strictly forbidden to treat on the first day in England?

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    Re: What is known to 'mess up' TB tests

    The Tb skin test is designed to promote an immune reaction, so giving the animal any other product that may promote or stress the immune system or animal for that matter may cause a 'false' reaction. We do our vaccinating on the second day as I don't want to produce any false results for the sake of getting it all done on the first day.

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    Senior Member Cowabunga's Avatar
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    Re: What is known to 'mess up' TB tests

    All my cows had their inspection day yesterday. Vaccinated all for BVD and Lepto as they went through the crush, including the youngsters who had their first dose six weeks ago.

    One damned inconclusive for re-test in six weeks. The very same cow that was inconclusive last year. She is drinking in the last-chance saloon!
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    Re: What is known to 'mess up' TB tests

    Quote Originally Posted by Cowabunga View Post
    All my cows had their inspection day yesterday. Vaccinated all for BVD and Lepto as they went through the crush, including the youngsters who had their first dose six weeks ago.

    One damned inconclusive for re-test in six weeks. The very same cow that was inconclusive last year. She is drinking in the last-chance saloon!
    I had 3 last yr who were very very very close on their re-test after failing first as inconclusive, they went to help fill Ginsters pie's last week before my test in a weeks time! Shame but being shut down makes life difficult for us with too many animals about.

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    Senior Member Cowabunga's Avatar
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    Re: What is known to 'mess up' TB tests

    Quote Originally Posted by miketm150 View Post
    I had 3 last yr who were very very very close on their re-test after failing first as inconclusive, they went to help fill Ginsters pie's last week before my test in a weeks time! Shame but being shut down makes life difficult for us with too many animals about.
    We are told to be efficient and being closed down is far from being 'efficient'. So if it comes to it, I'm not going to bleed, considering our dear Government hasn't got the balls to sort this issue. It's survival of the fittest.
    The Duck 2015

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    Senior Member greysides's Avatar
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    Re: What is known to 'mess up' TB tests

    Quote Originally Posted by Cowabunga View Post

    One damned inconclusive for re-test in six weeks. The very same cow that was inconclusive last year. She is drinking in the last-chance saloon!

    I would never trust an inconclusive, even one that had passed a retest.

    I've seen too many animals with similar readings, under a more severe interpretation, go to the factory and show lesions.
    History is a race between education and catastrophe.H. G. Wells.

  11. #11

    Re: What is known to 'mess up' TB tests

    Sounds like what a vet would say. I know numerous farms that still have their inconclusives, including ourselves.

    Personally I have no faith in the test or it's interpretation. The only way to play it safe is to get out of bovine stock.

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    Re: What is known to 'mess up' TB tests

    Quote Originally Posted by Cowabunga View Post
    We are told to be efficient and being closed down is far from being 'efficient'. So if it comes to it, I'm not going to bleed, considering our dear Government hasn't got the balls to sort this issue. It's survival of the fittest.
    Our dear government couldn't fight its way out a wet paper bag if their lives counted on it. As usual the problem will get sorted by fair means or foul in some cases I'm sure. And talking efficiency I'm not sure the cost of the pilot cull could be interpreted as 'efficient' in any aspect.

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    Senior Member greysides's Avatar
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    Re: What is known to 'mess up' TB tests

    Quote Originally Posted by Treemover View Post
    Sounds like what a vet would say. I know numerous farms that still have their inconclusives, including ourselves.

    Personally I have no faith in the test or it's interpretation. The only way to play it safe is to get out of bovine stock.
    You know it is.

    Faith in the test........well, I've gone through the gambit from little faith to sufficient faith. I've worked in three areas of Ireland and come to my own conclusions.

    From the point of view of trying to stay rid of a disease, especially one circulating in the general area, I'd hold to my conclusion. Yes, sometimes it will be a sacrifice of an innocent but sometimes it will be dodging a bullet.
    The problem with keeping inconclusives is that you don't know the hour or the day when they'll leave you down and allowing for the possibility of animals becoming 'anergic' (infected, not-reacting to the test, most likely contagious). These anergics are financially disastrous.

    There may be a case in certain locals for going gently on them due to local soils harbouring apathogenic family members but this one is a hard to call except over time.

    Getting out of cattle is a tactic that has had to be used in the past.... glens of Wicklow, in particular. Not a possibility in all areas though.
    History is a race between education and catastrophe.H. G. Wells.

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    Re: What is known to 'mess up' TB tests

    [QUOTE=greysides;216820]
    The problem with keeping inconclusives is that you don't know the hour or the day when they'll leave you down and allowing for the possibility of animals becoming 'anergic' (infected, not-reacting to the test, most likely contagious). These anergics are financially disastrous.

    Would such 'anergic' cattle then show with lesions when disposed of as cull cattle - I suppose old cows - pre 1996 cattle that are taken out of the food chain are not tested or looked at by the knackerman for bTB? if they went through the slaughter house would the lesions be there?

    But back to my original post, are there written guidelines as to what not to do, which may interfere with a bTB test?

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    Senior Member greysides's Avatar
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    Re: What is known to 'mess up' TB tests

    Quote Originally Posted by Socksitis View Post

    Would such 'anergic' cattle then show with lesions when disposed of as cull cattle.
    They would, if they could be found. The lesion can be very small and it can be in a spot not checked as a part of the normal PME.
    History is a race between education and catastrophe.H. G. Wells.

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    Re: What is known to 'mess up' TB tests

    [QUOTE=Socksitis;216832]
    Quote Originally Posted by greysides View Post
    The problem with keeping inconclusives is that you don't know the hour or the day when they'll leave you down and allowing for the possibility of animals becoming 'anergic' (infected, not-reacting to the test, most likely contagious). These anergics are financially disastrous.

    Would such 'anergic' cattle then show with lesions when disposed of as cull cattle - I suppose old cows - pre 1996 cattle that are taken out of the food chain are not tested or looked at by the knackerman for bTB? if they went through the slaughter house would the lesions be there?

    But back to my original post, are there written guidelines as to what not to do, which may interfere with a bTB test?
    Comes on our appointment letter. Don't dose or give any medicine unless under supervision of vet untill test is completed.
    I'm assuming you're not wanting to mess up the result of a test?? Have heard of people injecting animals with stuff to make lumps disappear before vet sees them but i'm sure that's not what you're on about as that is illegal.

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