Testing

There are several tests available for FeLV. All require a visit to your vet—who will take a blood sample, or possibly a sample of saliva or tears—and all are fairly reliable. But they're not perfect. For example, a positive test result may not be cause for immediate panic. One common quick-screening test, for example, the enzyme-linked immunosorbent assay (ELISA), has a rather high rate of false positive test results.

So if you have a cat that tests positive on the ELISA, you should have your vet run another test utilizing the immunofluorescence assay (IFA) or the virus isolation method; either method is a more reliable test than the ELISA. (Also, keep in mind that an animal that tests positive could be one of those that will eventually rid itself of the infection.) To verify the result, I recommend a retest whenever Kitty has had one positive test—making sure, of course, to keep the cat isolated during the "wait and see" period.

If, however, the IFA or the virus isolation test remains positive after repeated testing (say, after two or three tests over no more than six months), your options aren't appealing. Most veterinarians recommend that cats testing positive be put to sleep. Since the cancer of FeLV is almost always fatal, euthanasia is often the best choice to make. Remember, too, that a cat testing positive can pass the disease on to other cats in the neighborhood.

Also, although there is no real scientific evidence to support them, some vets (myself included) fear that exposure to cats with FeLV may increase your (or your kids') risk of getting cancer. I want to stress that there's nothing definite to support this suspicion yet, and, in fact, many vets and medical researchers say there is positively no connection. But species-specific viruses do sometimes take evolutionary leaps and infect other species (FeLV, for example, is thought to have developed originally in European rats). And some surveys do point a somewhat incriminating finger—in fact, enough surveys to make more than a few vets pretty antsy about trying to treat FeLV-infected cats in households where there are children.

I recommend annual testing of all cats that are in multiple-cat households, or that run outdoors and are therefore exposed to the cat population at large.

Treatment

There are ways to treat FeLV, but unfortunately the treatments are often expensive, lengthy and painful to both owner and pet—and the results are seldom rewarding. If you've thought over the options and still want to try treatment, discuss this with your veterinarian.

The best—and some would say, the only—way to prevent the spread of FeLV within a household of cats is to put to sleep all cats that test positive, to clean the premises with ordinary disinfectants or household bleach, and to not bring in any new cats until all the household cats have had two negative FeLV tests over a span of six months' time.

Prevention

There is better news on the prevention front. An FeLV vaccine has been developed in recent years, and initial results seem encouraging indeed. Plan on a vaccine program that includes two or three kitty injections to begin the immunity and then an annual booster shot. As I write this, there's some question, particularly among vets on the West Coast, about the vaccine's ability to adequately produce a true immunity. But for now, anyway, it is the best weapon we have to fight FeLV.

The other element in prevention, of course, is the cat's own active immune system. Since some cats are known to be immune to the virus, it only makes sense for cat owners to do everything possible to enhance their pets' natural immunity. Here's where an active holistic health program—one that includes proper nutrition, adequate exercise and a loving, caring living environment—is critical.