Conflicting feline leukemia test

Hello all,

I have this male cat named Big. He was tested for feline leukemia and the snap test gave a weak positive result. My vet decided we should wait 3 months before retesting to see if his immune system was able to work it out of his system. 3 months later we do it again and it comes up a weak positive. I want to have a blood sample sent out but the vet doesn't think it will matter. I have them do it and this comes back negative. Doctor wants to wait 6 months to see what happens with his immune system. Does he have it and he is just a carrier? Which test is right? Confused!

Thank you.

Hmmm. interesting question.  I don't have an answer for you   Honestly, I would think the blood test would be the better of the two, and that one was negative, so that would make me think he is neither positive nor a carrier.  BUT,...

What did your Vet say after the blood test came back negative, other than to check again in 6 months?  Was he surprised by the results?  

He thought he has the virus still in some way and that more time was needed. I also have another cat and they have been separated since i got them. They both came from the same home but Beezle doesn't have it.

lorimer71 said:

Hello all,

I have this male cat named Big. He was tested for feline leukemia and the snap test gave a weak positive result. My vet decided we should wait 3 months before retesting to see if his immune system was able to work it out of his system. 3 months later we do it again and it comes up a weak positive. I want to have a blood sample sent out but the vet doesn't think it will matter. I have them do it and this comes back negative. Doctor wants to wait 6 months to see what happens with his immune system. Does he have it and he is just a carrier? Which test is right? Confused!

Thank you.

Click to expand...

Hi

It's a good question with a somewhat complex answer.  You had the Elisa test and your vet is correct i believe in wanting to retest that way.  The IFA test is more prone to false negatives than to false positives so if a cat test Pos on elisa, then a neg result on IFA isn't reassuring.  The article i am quoting from below suggests either a) retesting elisa with a different companies test kit or b) using the extremely accurate PCR test but notes that this test is subject to error if not handled extremely carefully.

My two cents, a weak pos result indicates exposure but does not prove infection and that in time you will either get a neg result (likely) or a pos result (less likely). If you keep getting weak pos results i would discuss the PCR test with your vet.  

From: http://www.sheltermedicine.com/node/43

Cats testing positive by the ELISA test on serum should ideally be retested either using an ELISA test from a different manufacturer or by sending the appropriate sample for an IFA test at a diagnostic laboratory. If both tests are positive, the cat is very likely persistently infected. To be absolutely certain, cats can be held and retested after 30 days if resources are available and the cat can be appropriately housed and isolated (for the protection of the cat and population; see below). Because the IFA is less sensitive (more prone to false negatives) than the ELISA test, a negative IFA result in a cat testing positive ELISA can not be taken as an indicator that the cat is not infected. If the ELISA test is positive but the IFA results in a negative result, both tests can be repeated in 30 days.  If this strategy is used, a plan should be made at the outset and clearly communicated to staff and foster parents regarding what will happen with cats that test persistently positive after the 30 day hold. A PCR test can also be run to help resolve any conflicts in the tests. PCR is very sensitive, so a negative test result run by a reputable laboratory indicates infection is unlikely. However, because PCR testing is very sensitive to laboratory error, correct sample handling and laboratory quality are extremely important.

And: http://www.vet.cornell.edu/fhc/Health_Information/brochure_felv.cfm

Thank you for the info. Is there anything i can do for the cat to help his immune system?

lorimer71 said:

Thank you for the info. Is there anything i can do for the cat to help his immune system?

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Give him a low stress environment, that's probably number one.  Is he the only cat in your home?  Also decent food, avoid exposure to other illnesses and illness causing vectors like fleas, worms, other cats, mice, and he should stay indoors.  but he is likely to test negative in time, and even if he becomes fully positive, there are 2 stages to FeLV, and as an adult is not as likely not to progress to stage 2.

Also, Transfer Factor is supposed to be good for helping boost the immune system.  Here's a thread on it, albeit it's pretty old:  http://www.thecatsite.com/t/181429/anyone-ever-use-transfer-factor

Thank you on the Transfer Factor. I will give it a try after looking into it  a bit more.

Also I didn't know the stage 2 of  disease might not show up. I thought it was the natural progression of it. I really want to put the 2 cats together. They use to be at their old home, but I won't till I know where Big is really at. Of course if he still has it in 6 months I'll just have to keep them apart.

Best,

Richard

lorimer71 said:

 
Thank you on the Transfer Factor. I will give it a try after looking into it  a bit more.

Also I didn't know the stage 2 of  disease might not show up. I thought it was the natural progression of it. I really want to put the 2 cats together. They use to be at their old home, but I won't till I know where Big is really at. Of course if he still has it in 6 months I'll just have to keep them apart.

Best,

Richard

Click to expand...

Yup, see links above.