When I was in vet school at the Ohio State University College of Veterinary Medicine in the late 70’s, Feline Leukemia Virus was a frightening threat to the health of cats. Most cats went outside in those days. There was no treatment for FeLV, and no vaccine. It seemed that every stray cat had the virus, and we saw many different manifestations of disease caused by the virus.

Just about the time I graduated the virologists at OSU invented the first vaccine against Feline Leukemia Virus. Finally-we could take action against the virus! Since there was no sense in vaccinating a cat who was already infected, it became standard policy to test every cat for FeLV before vaccinating. The recommendation was (and still is) to euthanize cats who were positive for FeLV, and vaccinate cats who were negative for it.

Time went by. More and more cats were vaccinated against FeLV. At the same time, fewer pet cats were spending much time outdoors. The incidence of Feline Leukemia began to decline. We became more sophisticated in our understanding of the course of the disease, how it was spread, how it affected a cat’s immune system, etc.  It became more and more unusual to find a healthy cat who was FeLV positive on our screening tests. And half of those cats, when tested with a confirmatory test, turned out NOT to have the virus. They were falsely positive on the screening test.

In 2001 I entered the field of shelter medicine. I worked at a large shelter which only tested healthy cats who were “at risk” of being exposed to FeLV-strays, female cats with litters, or cats from households of greater than three cats. During my years there we must have tested 10,000 cats for FeLV. Of the 10,000 cats tested, all of whom were likely to have been exposed to the virus, fewer than 100 were positive.

That is less than 1 percent.

I have been at Prairie’s Edge Humane Society for two years. In that time, we have tested more than 230 cats and kittens for FeLV. All have been negative.

The screening test for FeLV is not cheap. In fact, except for spaying and neutering, it is the single most expensive thing we do to prepare cats for adoption. It’s hard to justify continuing to do an expensive test when it is clear that the vast majority of the time that test is going to be negative, and if it IS positive, it is wrong 50% of the time.

In these days of economic decline, it is vital to use every dollar we have to take good care of as many animals as possible. The money we save by forgoing FeLV tests will help buy vaccines and sutures. It will help us fund our spay/neuter programs. It will help us heat our building and feed our animals. It is a resource we can put to better use.

Remember – I am talking about using shelter resources wisely. There is a huge difference between what is good for an individual cat and what is best for a shelter caring for cats. When your veterinarian recommends testing your cat for FeLV, he or she knows what is best for you and your cat. In the perfect world, shelters could afford that level of medical care. In the real world, we do the best we can.

Terri A. Derr, DVM

Director of Operations/Staff Veterinarian

Prairie’s Edge Humane Society