Anyone ever have a false negative CL test?

Discussion in 'Goat Management' started by 4kids, Jul 19, 2010.

  1. 4kids

    4kids New Member

    844
    Jul 21, 2009
    Has anyone done the research on this??? I know false positives are pretty common but what about false negatives?

    Thanks
     
  2. kelebek

    kelebek New Member

    Oct 5, 2007
    South Texas
    Actually false positives on blood testing is very rare if going through a reputable lab. I know of one lab that is very known for incorrect test results - but if you do state vet labs you are pretty safe :)
     

  3. lissablack

    lissablack New Member

    Nov 30, 2009
    My vet who is a life long goat person and a mentor to me says the blood tests for CL are so inaccurate in both direction as to be a waste of money. On the other hand I don't know what else you would do if you suspected it. There are false negatives. There are two kinds of test, Elisa and Agid, I don't know if doing both would help. there might be a new kind of test coming, a pcr test, which might be more accurate, but don't know if that even exists.

    So yes there are false negatives and false positives for CL blood tests. Cultures of the pus from an abscess are usually accurate.

    Jan
     
  4. StaceyRosado

    StaceyRosado Administrator Staff Member Supporting Member

    Oct 4, 2007
    NJ
    I could see there being a false negative in a clean animal (no abscesses) but if an animal has an active case of CL (apparent abscess) then I would believe that it would show up in the blood test. Also if there is an abscess that you are unsure about and you test while the abscess is there then I would believe whatever reading you get - positive or negative.

    But Jan is right culture of the abscess is the best option especially when dealing with CL
     
  5. RunAround

    RunAround New Member

    Feb 17, 2008
    Massachusetts
    False negatives happen all the time in testing, as well as false positives. :(
     
  6. Perfect7

    Perfect7 New Member

    Apr 19, 2010
    South Georgia
    When our doe had a suspect cyst we had bloodwork done. She had a weak positive with a level of four. The lab (some university out of texas, I forget which right now) told me on the phone that a goat with an active CL outbreak would have a level of at least 16, usually much higher. They said this meant prior exposure, and most likely from vaccination, but she did not have CL.
    I have no idea what a positive level would have to be for no active outbreak, and if they would consider a weak positive to be a true positive....or the result of vaccination. It would be nice to know.
    Clear as mud, right?
     
  7. 4kids

    4kids New Member

    844
    Jul 21, 2009
    Okay- What else can cause an absess then? I tested eveyone for CL and all were neg. I have a goat that has an absess on her check/jaw. It isn't in the popping stage right now. what else could it be?
     
  8. StaceyRosado

    StaceyRosado Administrator Staff Member Supporting Member

    Oct 4, 2007
    NJ
    they can get it from a thorn or splinter - they can get it from a bug bite.
     
  9. 4kids

    4kids New Member

    844
    Jul 21, 2009
    Its been a few weeks. Not going away. According to my research the chance that this could be a false negative with an abcess is very small. Is this correct?
     
  10. kelebek

    kelebek New Member

    Oct 5, 2007
    South Texas
    Does the animal have a fever at all?

    You can tap it in a sterile environment and sent in the exodus for testing. Could be as stacey said - from a splinter or salivary gland - but better "to suspect" and take precautions!

    There are "certain" labs that are definately known for giving incorrect results - so make sure you use a state lab.

    IF you tap it - if it an odor - definately not CL
     
  11. 4kids

    4kids New Member

    844
    Jul 21, 2009
    No fever- acting fine- I did testing at Waddl. Abcess is hard feeling not squishy- like a marble.
     
  12. kelebek

    kelebek New Member

    Oct 5, 2007
    South Texas
    Do you have a vet that could lance it or do a tap and send it to WADDL for testing?
     
  13. RunAround

    RunAround New Member

    Feb 17, 2008
    Massachusetts
    FYI, I drew the blood on her goats myself and it was sent to WADDL... but WADDL has been wrong before and has admitted that to me..... They made me spend a LOT of money because of their inaccurate results....

    Honestly, I think the bump is a splinter or something taking a long time to work itself out. BUT if you think she was tested false negative(which can happen) I would take her into the vet where they can sample it and send it off. Thats the ONLY way to know for sure if it is or isn't CL. :)
     
  14. 4kids

    4kids New Member

    844
    Jul 21, 2009
    Good to know- I am just a worry wart. I will see if it becomes softer and then take her to the vet.
     
  15. Perfect7

    Perfect7 New Member

    Apr 19, 2010
    South Georgia
    Our vet seems to think the persistent lump on my does' neck (right where the jaw and neck meet and in the lymph nodes) is most likely a benign cyst. She doesn't want to operate because of the location to the major blood vessels and it may actually be IN a lymph node. It's not causing any problems, so it stays.