Feline Leukemia Test

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Feline Leukemia Test

vetinfo.com

vetinfo.com

Feline Leukemia - testing accuracy

Q: Dear Dr Richards I breed Bengal cats. My tom has been tested as has the other animals that he lives with. My Queens are all healthy and live completely isolated indoors. I have had two people that have purchased kittens from me say that their kittens have tested positive for fel leuk. One was 2 years ago, and the other is recent. Can you explain the limitations of the tests that are done? Is it possible that these are falible and that the cats are not in danger or dangerous. The cat that was diagnosed 2 years ago lives with other cats, and has not infected anyone either. They are all vaccinated yearly. What is happening? M

A: M- There are a number of possible explanations for the situation you are encountering. The screening tests used for feline leukemia in the office in veterinary practices do have a small percentage of false positive results. The exact percentages vary from test to test but they are probably between 1 and 5%. Since a lot of cats will be tested who won't have the disease and only a small number of cats will be tested who do have the disease it becomes somewhat likely that a test that is positive is inaccurate. All cats should be tested at least twice when they show up positive on feline leukemia testing. The other problem is that cats can be negative on a test for feline leukemia and then become positive due to recurrence of a suppressed infection, a new infection or because of a false negative result to begin with. False negative tests are supposed to be less common than false positives, though. The current thinking is that most cats are infected with feline leukemia virus when they are young, less than one year of age. This means that there is a chance that one of your cats is positive and you do not realize it but also a chance that the kittens contacted the disease away from your place === along with the chance of false positive tests. If you can talk the kitten owners into retesting and then see what the results are you might have a better idea of how much need there really is to retest your cats. Mike Richards, DVM

Saliva tests for feline leukemia virus infection

Q: Hi, I would like to know if the saliva test for FeLV is good enought. I heard of this test throug the internet. Please let me know if the blood test is more reliable than this test.. Yury

A: Yury- Sometimes information relating to testing procedures changes rapidly and it is possible that there is new information that I am not aware of but my current understanding of the saliva tests for feline leukemia virus infection is that they are still plagued with both false positive and false negative results to a much higher degree than the screening blood tests. Mike Richards, DVM

Feline leukemia test

Q: About 2 1/2 months ago I lost a 3 year old cat to feline leukemia. He was a cat that I rescued from a city pound when he was about 6 weeks old. I took him to the vet about 2 weeks after I got him and at that time I was told that he had feline leukemia. The Vet told me that he could live a long time with that or a short time with it...his was too short. Anyway on Saturday I purchased a Birman kitten and was told that she was in good health...she had not been tested for feline leukemia or FIP as both of her parents had tested negative. I took her to my own vet on Tuesday and they tested her and vaccinated her...however they did 2 different tests on her as they said the first leukemia test showed a faint positive so they did another test they said that tested for feline leukemia and feline aids. They said this test was negative and that it is more reliable than the first test they did. So why do they do the first test if it is not very reliable. By the way, I had thrown out all of the first cats things when I had to put him to sleep so she had new litter box and feeding bowls, ect. Any thoughts on this?

A: I can't say why your vet uses two different tests for feline leukemia. We keep two different tests for heartworm disease specifically for retesting of positive results using a different testing method, though. Usually on ambiguous feline leukemia tests we recommend retesting in a month or so. In theory this should allow the cats who are infected but whose immune systems will kill the virus to clear it from their bloodstream. Cats early in an infection whose immune systems don't win should get worse. The only problem is that some cats sequester the virus out of their bloodstream, making the test negative even though they are infected. There is no foolproof way to test for feline leukemia, yet. Feline leukemia virus does not live long at all outside of the cat -- probably less than a few seconds. There should be no way your new kitten can catch this disease from your previous cat. Throwing out the food bowls, etc., was probably not necessary but being cautious isn't a bad idea. Michael Richards, DVM

Last edited 04/20/04


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Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...

 

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