Question about felv/fiv testing

Ok everything I thought I knew about the testing and results was shot down today by a vet here. Basically she said that it is useless to test before they are 1 year old. Also she said that is a kitten under a year old tests positive then that's that and they are pretty well certainly positive but if the test negative it doesn't mean anything cause they can change to positive within the first year.

I always thought false positives happened a lot and I have always thought that they can be tested early in life and if negative then there is nothing to worry about and if positive to retest after 3 months. This vet has me completely confused and questioning everything. :confused:

Please any input here would be appreciated. I also emailed my vet in Canada and asked him a bunch of stuff about this too.

Thanks guys
Michelle

I was told no point to testing prior to 6 months; and a positive at that point may be a negative later on.

I am going to do some checking again and post what I find.

Would like to clarify, BOTH tests, leukemia AND aids? wow. I"ll post back in a bit after some googling

thanks sandra...yeah it jsut didn't seem right what she said about a positive pretty well never turning to a negative. and vice versa. Both tests were what I was wondering about. Thanks a million

Michelle

:o Now you have me wondering.. I just got wittle Rastus Gem from the Vets & my Vet told me he was tested for all & was all negative.. Now he goes back this coming Sat 16th & thats a very good question..

Very good question, because I have a little 4 month old female that I was going to ask the vet to have her tested for feline aids and leukemia tonight when I bring her in.

I'll have to keep a watch on this thread. :)

I've had this test done at all ages and the vets never said "dont do at certain ages", they all said TEST them. Cindy was tested at what we think was at 6 months old approx age, we werent sure when exactly she was born. Stephen was tested at 7-8 months old (paperwork isnt infront of me at moment, going by memory). Skinny was tested at approx 1 year old.
Thumper was tested at 2 years old.
When Butterscotch was diagnoised with Feline Aids we had everyone (Thumper and Skinny) tested again.


I think it's a matter of how knowledgeable the vet is about things the younger vets seems to be more "up to date" on stuff than older vets (my experience), but when it comes to testing for stuff they are all in agreement per my experience.... Test them regardless of age.

My advise is to test at any age is better than NOT testing them at all, just seems like good common sense to me.

Michelle

I had two kittens test positive for FeLV. Subsequently, I learned a lot.

Here is an authoritative source:
http://www.aafponline.org/resources/...Guidelines.pdf


Here's some of the important things I learned:

A snap test (also known as a combo test) can have false positives. A negative is reliably accurate, not a positive. There are additional tests you can have done (the IFA test). The American Association of Feline Practitioners recommends confirming a positive Snap test result with the IFA test. If it's negative, then retest 60 days later.

The problem with testing kittens or cats is this:

If they were outside, they could have been recently infected, but it will not show up on the test. If they are going to develop it, it will take a while. It's like being exposed to the flu...you don't get sick immediately.

Wishing you and your kitties the best.
Pat

Hi all -

I found the recommendations from the American Association of Feline Practitioners/Academy of Feline Medicine. Those are the ones I will go with here. FIV and FeLV have different guidelines.

Feline Leukemia
Link: http://www.vin.com/mainpub/feline/aafpfelvdx.htm
Summary:
• Kittens can be tested at any age
• Vaccination with FeLV vaccine does not interfere with the FeLV test

Initially it is given to kittens after 9 weeks of age, and reboostered 2-4 weeks later. If the second vaccine in the 2 vaccine series is given greater than 4 weeks after the first, an additional vaccine needs to be administered 2-3 weeks later. After the initial series, yearly boosters are given. If your cat goes outside frequently, we recommend yearly FeLV testing along with vaccination.
No vaccine can be guaranteed to be 100% effective, so we recommend separating any FeLV positive cat from FeLV negatives cats, even if the negative cats are vaccinated.
*******************
It is vital that a vaccination certificate is not accepted in place of a negative FeLV test.
*******************

This is the part I think that vet may have been referring to:
The blood test itself is quite accurate, but not perfect. Because cats can be transiently infected, it is possible that a cat will initially test positive for FeLV, and then recover and test negative at a later date. This is especially likely to occur in otherwise healthy kittens. In most healthy cat populations FeLV is quite uncommon, and this leads to an increase in the relative number of false positive results. In some studies, over half of FeLV positive results obtained by veterinary hospitals from healthy cats were incorrect.

The blood test may also falsely identify recently infected cats as negative. To be absolutely certain, cats must be tested 1-3 months after their last known exposure. False negatives are more common when samples other than blood (e.g. saliva, tears) are used and when multiple samples are pooled.

Unlike FIV, testing for FeLV may be performed at any age. As mentioned, infection may take up to 1-3 months to develop, so results in young kittens are slightly less reliable. Samples should be tested individually; testing representatives from litters or pooling samples significantly decreases test accuracy.

Here is the info from the SAME entity listed above, for Feline AIDS.

Link: http://www.vin.com/mainpub/feline/aafpfivdx.htm

Summary:The blood test is quite accurate, but false positives and occasionally false negatives do occur. In healthy, low-risk populations FIV is quite uncommon, and this leads to an increase in the relative number of false positive results. The blood test may also falsely identify recently infected cats as negative. To be absolutely certain, cats must be tested 1-3 months after their last known exposure.The test can not be accurately interpreted in young kittens.
There is currently no test available to distinguish between infected cats and cats that have been vaccinated for FIV.
If resources allow, cats testing positive by the ELISA test should be retested by sending the appropriate sample to a laboratory for IFA or western blot analysis. In high-volume shelters, holding cats for retesting may not always be practical. At the very least, the ELISA test should be repeated to ensure that correct technique was used

Maternal antibodies may interfere with FIV testing in kittens. The literature is in disagreement as to when FIV screening may be performed: maternal antibody interference can rarely occur up to 4 months but has disappeared by 6 months. As mentioned, even in adult cats infection may take up to 1-3 months to develop, so a final test should be performed 3 months after the last known exposure to be absolutely certain. Samples should be tested individually, pooling samples significantly decreases test accuracy.

There is a vaccine available for FIV, although it is not 100% effective in preventing infection. FIV vaccinated cats will test positive for FIV on all currently available tests.

Thanks Sandra you have gone above and beyond. I appreciate it greatly. :)

Where I work we test cats 4 months and older. Positives are retested 1-2 months later.

If they test negative for FELV we go ahead and vaccinate. We don't use the FIV vaccination where I work because it causes a cat that has been vaccinated to test positive for the disease since the test (SNAP combo) doesn't know the difference between the actual disease and the vaccine immune response. (BTW this is not the ONLY reason our hospital doesn't use that vaccine)

That's about all I know about it, although if I get a chance I'll ask the head vet next time I'm at work because now I'm curious. lol

FIV seems to be endemic in southern Westchester. We've had several false positives from there; the kittens probably had antibodies from the mothers. Western Blot tests, while slow and expensive, are very good for confirming the results. The kittens in question did throw off the virus and tested negative at 6 months.

If we followed the one year old protocol, we would not be able to adopt a single kitten. Many vets in our area will test at 8 weeks, but call the results "at risk" and say they are not 100% accurate. Well, no test is.

Michelle,

Sorry, but I beg to differ with your vet.

I had a kitten, 9 weeks old who was tested for both. She tested POSITIVE!! :eek: I adopted her from a rescue organization as a feral baby who was bottle fed. To say I was devastated is an understatement. Debi, the president, told me to bring Marina Mar to her and she would have blood taken and sent out to a lab. "Snap" tests, as they are called, often test positive if done before 4 months of age.

The second, more reliable test turned out NEGATIVE!! Have them do the blood test. PLEASE!!

Quote:

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Originally Posted by moosmom

Michelle,

Sorry, but I beg to differ with your vet.

I had a kitten, 9 weeks old who was tested for both. She tested POSITIVE!! :eek: I adopted her from a rescue organization as a feral baby who was bottle fed. To say I was devastated is an understatement. Debi, the president, told me to bring Marina Mar to her and she would have blood taken and sent out to a lab. "Snap" tests, as they are called, often test positive if done before 4 months of age.

The second, more reliable test turned out NEGATIVE!! Have them do the blood test. PLEASE!!

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You know Donna it seems that the vet was slightly confused which is what I believed in the beginning. The is the first practice she has been involved in as a 'vet' per say. She was involved more on an assistant level before now.

As it goes right now I am waiting to hear from my vet in canada. I emailed him friday and he got back to me saying he tried to call but could not get through. So he said he is going to go over my email this weekend and get back to me with everything I want to know tomorrow(monday). Vega is not going anywhere. She is staying with us unlesss it is absolutely necessary to rehome her. She will be tested for sure. I am just waiting for Dr.D (my vet in canada) to tell me the best time to go so.

Thanks so much everyone
Michelle

We've had kittens test positive, only to turn out negative later on.

One of my fosters, Piglet, tested positive 2 or 3 xs when the family who originally had him tested him at her vet's office. I had him from the time he was 1 1/2 to 2 1/2yrs old. We retested him 3xs. He was negative 3xs in a row .

From what I was told by the vet's office was that it was possible to test a false positive, but NOT possible to test a false negative. Same with human HIV tests. You can't test negative and not be negative. If the antibodies are there, they will be picked up by the test, even if it's light.