Re: Being a worry wort

[Meligar]

If the in-house ELISA test didn't catch your cat's positive FeLV status, the follow-up test would not have caught it either. At that point, if the cat had a latent infection (as opposed to being truly negative and catching the virus after the initial test), the only test that might have caught it is an invasive bone marrow test. That test is not routine.   Generally, you test twice if a cat comes up positive on the first. If the cat comes up negative on the first, it's safe to assume that it's accurate as far as it goes. What we need to bear in mind is what these tests actually detect. The ELISA test looks for antigen in the bloodstream. If a test comes back negative, it means that there is not sufficient antigen in the bloodstream for the test to detect, or there is no antigen. The limitations of the test are that it only tests blood and that it has a limited threshold for the amount of antigen necessary to trigger a positive. It is my understanding that the PCR tests for smaller traces of antigen, but we have heard that it's unreliable and not usually recommended. The IFA tests for actual virus/active infection but again, only in the blood.   None of these tests help in the case of a cat who is latently infected with virus sequestered in an organ or bone marrow. For that, one would need a DNA test and that is not routinely performed if you have no reason to believe that the results of the ELISA do not tell the true tale, e.g., you have a cat who is sick and all symptoms point to FeLV, but the ELISA says negative.   Someone please correct me if any of this is inaccurate; this is my understanding of what I have read.   Melissa in NJ     In a message dated 1/23/2005 2:18:46 P.M. Eastern Standard Time, [EMAIL PROTECTED] writes: Yes, they were adults, all indoor kitties, and no they hadn't been vaccinated. I had quarantined the kitten until he could be tested and was very happy when his ELISA came up negative. My vet said false negatives are rare so in this case the ELISA didn't pick up the virus. I was angry with the vet because she said it wasn't her policy to do two tests, which in the case of a stray kitty adviseable. They kitten was a stray I found in a parking lot. About a year later he had a dental and the vet thought the stress of the anesthesia activated the virus. I had always heard the FELV vaccine was a little dangerous; although they were all vaccinated after little Henry Lee turned positive to no ill effect, even my tiny hypernatremia kitty, Sylvie. Bonnie