What is FeLV/FIV?

When you adopt a cat from a shelter or rescue, they should always have been tested for FeLV and FIV. If the results are negative for both, the kitty is cleared for adoption and most adopters never give their status a second thought. But, what are these diseases, and what happens to those who test positive?

In short, a cat with either disease has a good chance at living a long and happy life, if given the chance.


Feline Immunodeficiency Virus (FIV)*

FIV is a feline virus spread from mother to baby or through deep bite wounds, typically incurred in aggressive fights. It can also be spread via mating. It is NOT contagious to humans or other non-feline animals. Typically, fewer than 5% of cats test positive for FIV, but it can be higher in some feral communities.

FIV is slow-acting, and a cat with the disease could be symptom-free for months or years before the virus becomes active. When active, FIV attacks a cat's immune system and leaves them prone to secondary infections. FIV cats with an active virus may become sick and become sicker and sicker, or they may go through periods of sickness and then be fine again for a varying amount of time.

Symptoms include lethargy, sneezing, inflammation of the mouth, fever, anemia, weight loss, abnormal stools, and numerous other issues. If your cat is suffering from any of these symptoms, be sure to talk to your vet.


Feline Leukemia (FeLV)*

Feline Leukemia is a relative to FIV, but generally considered more serious. Like FIV, FeLV attacks a cat's immune system, and can cause blood disorders or cancers. The symptoms are the same as those for FIV, but FeLV is spread much more easily. FeLV can be spread through any bodily fluid, including through mating, sneezing, mutual grooming, shared water bowls or litter pans, or a mother nursing her young. The virus does not live long outside of a cat's body, and cannot be caught by humans or animals other than cats. Like FIV, fewer than 5% of cats test positive for FeLV, but it can infect entire colonies of feral and stray cats if left unchecked. The rural areas SAM services unfortunately do have higher rates of infection than most of the United States, according to local veterinarians.

Kittens are much more likely to become infected by FeLV than adult cats, though adults can still get it through biting/mating or through prolonged exposure to an infected cat.

Cats with an initial infection may have no symptoms for days, months, or even years before the virus goes active, after which it is typically a fast decline. There are some treatment options which can prolong an ailing FeLV cat's life, but they are generally short-term and costly, so many vets will not recommend them.

Kittens born with FeLV typically have low survival rates, but the chances for adults are significantly higher. The median lifespan after diagnosis is around 3 years, though this is skewed since many are not diagnosed until they are already displaying unusual symptoms. Now that most rescues test EVERY cat on intake, whether displaying symptoms or not, it is easier to know very early on and be aware of what signs to watch for. Some cats, when kept indoors and cared for properly, can live more than 15 years past diagnosis before the virus goes active.



There is a single yearly vaccination which offers a significant reduction in cats' vulnerabilities to both FIV and FeLV, and it should be available at any veterinary office. If your cat has a good risk of being exposed to other un-tested or positive cats, it if imperitive that you vaccinate them. If your cat is kept indoors and never slips outside, their risk is negligible, but it only takes a door-running cat one bite from an infected stray to become infected themselves. If your adult cat has low risk factors (your cat is fixed, they are kept indoors-only, and aren't door-bolters), it is generally not recommended you vaccinate them for FeLV/FIV, as the vaccine does have a risk of side-effects greater than other typical (and mandatory) cat vaccines.

The vaccination is not 100% effective -- generally around 75% if directly exposed to the viruses -- so while it is definitely worth getting if your cat is at risk, it is still important to keep your cat away from others which may harbor disease. The best way to do this is to keep your cat indoors-only, and always keep new pets separated from old, proven-healthy ones until they can be tested and proven negative themselves.

While calm, fixed FIV cats can be kept in the same house as healthy cats since that disease is only spread via deep bite wounds, FeLV cats should be kept totally separate from healthy cats because FeLV can be spread via any bodily fluid, including via grooming or shared water bowls/litter boxes. FeLV cats that get along with one another can be kept together.

Testing for both FIV and FeLV is a fast and easy process, also available at most vet offices for under $50. Generally, it only involves a quick blood draw, and one test strip is able to test for both diseases at the same time. If a new cat tests positive for FeLV but has no symptoms, it is worthwhile to test them again a few months later (or in kittens' cases, after they are at least 6 months old), because a cat may give a false positive if their immune system is fighting the disease and succeeds, avoiding long-term infection. Cats which are vaccinated for FIV may also give false-positives on some tests.


Care of an FIV/FeLV+ Cat*

Both diseases have no cure, but they can be managed and a cat with either disease can live a happy, normal life until the virus reaches its late stages.

When you adopt a cat with one of these diseases, or if your cat contracts one, the most important thing is to keep them indoors-only. Not only does this prevent further spread of the disease to other outside cats, but it can prolong your cat's life. Keeping them stress-free, away from other cats, comfortable, and on a good, processed cat food (no raw diets, since these can introduce dangerous bacteria) can limit your cat's exposure to secondary infections.

Regular vet visits are also imperative. Positive cats should see the vet at least twice per year for basic exams, to catch potential problems early-on. If a general cold or other viral infection can be caught early and treated, it is possible to prevent it from getting worse and to the point where damage is irreversible.

Finally, when adopting a cat with FIV or FeLV, it is important to know when it is necessary to let them go. Particularly in the case of FeLV, the disease can progress suddenly and quickly. If the cat is already suffering, or doesn't respond to antibiotics, discuss with your vet if it is worth continuing treatment. In the case of a cancer or other serious diagnosis requiring surgery or invasive treatment, some vets may recommend against continuing, as recovering from surgery or other treatments can be more difficult for a cat with an immune disease, and the final prognosis may be poor enough that it isn't worth forcing the cat to suffer longer.


Why You Should Adopt a + Cat

In the past, and in many cases still, the second a cat tests positive for FIV or FeLV, shelters (even no-kill shelters) will euthanize them because there is limited space for quarantine and these cats are historically harder to find homes for. In previous decades, these diseases (particularly FeLV) were believed to be instant death sentences. Today, though, it is recognized by most veterinarians that, with proper care, these cats can live fulfilling lives until their virus goes active. With increasing prevalence of foster care versus shelter care, FeLV/FIV cats can be separated from healthy cats and kept from the common viruses spread in shelters where many cats are kept in a close environment.

Cats with FIV and FeLV can live perfectly happy lives, living as long as a regular, healthy cat could, if conditions are good and they are lucky. They do not require an excessive amount of extra care, and typically do not cost much more than an average cat over their lifetimes (as long as you are aware of their diagnosis and work preventatively).

Even in the cases where the diseases progress rapidly, a cat who lives three months in an adoptive home before the virus goes active was given three happy months, filled with cuddles, toys, and love they wouldn't have gotten if they were immediately euthanized.

Just as there are fosters who want to give senior pets a home for their remaining years, there are incredible people who want to do the same for FeLV/FIV cats.



Consider adopting an FeLV or FIV cat, and give a second chance to cats who need one.

SAM has taken in and raised multiple FeLV cats, and found loving homes for them all -- so it is possible!  If you are interested in adopting one of these special cats (or two, or three!) and being a hero, give us a call or email. We have special adoption fees to thank those who are awesome enough to open their hearts to a special-needs kitty.



*Note: these descriptions are simplified for easier understanding. For more information, talk to your vet and look at other reliable online sources, such as PetMD or vet.cornell.edu. Keep in mind, though, that previous attitudes towards these viruses were much more pessimistic than modern understandings.

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