Living with FIV and FeLV
Caretakers are often called upon to find housing for cats that test positive for FelV and FIV. Some are afraid to allow any FIV or FeLV positive cats into the general population, into their own households, or even to continue to care for them at all. Based on what we know about these two diseases, there is no reason that “healthy”* appearing cats couldn’t be cared for and get to live a fairly healthy and contented life.
Cats are susceptible to two pathogenic (disease causing) retroviruses. One is FIV (Feline Immuno-Virus), the other FeLV (Feline Leukemia Virus). The term Retro refers to the fact that these viruses have the ability to insert their own genetic material and information into the host’s (in this case, the cat’s) cell DNA.
FIV is similar to, but not the same as, the Human Immuno-Virus (HIV) and can cause an immune deficiency in the infected cat. It is a lente virus, which means that, just as in humans infected with HIV, it takes a long time for this virus to begin to cause the bad effects that we see with infection.
FeLV is an oncornavirus, which means that it is capable of causing cancer in an infected individual. As part of the various syndromes seen with a FeLV infection, immune suppression can take place.
But FeLV and FIV are not the same, the progression of disease in an infected cat is usually quite different, the mode of transmission/infection and the likelihood of infection in an exposed cat are also quite different. This means that a cat with an FIV infection poses a very different risk to other cats than one with FeLV. The most commonly used test, often called the “combo test”, tests for both of these viruses at the same time, which sometimes leads to confusion about the difference between the two infections.
FIV is spread from cat to cat through biting and fighting. In essence, if no fights occur between cats, FIV is not going to be transmitted. FIV is not transmitted between cats by sharing meals, litter, or mutual grooming. In stable households or colonies where all the cats (especially the males) are neutered, fights are less likely and FIV positive cats can coexist with FIV negative cats for years without any spread of the virus.
FeLV is found in the secretions of infected cats, including in the saliva and urine. As a result, infection can be spread by direct contact between cats (mutual grooming, etc.) as well as contact with shared objects such as food and water bowls and litter areas.
Some basic rules to follow when keeping cats with one of these infections will help you provide a safe and healthy environment for all your cats. Because of the mode of transmission, FeLV positive cats should not be housed with other cats unless those cats are also FeLV positive. If you must keep them together, having the FeLV negative cats properly vaccinated against FeLV is highly recommended. Though this does not guarantee protection or that the infection will not spread, it is likely to provide some degree of immunity. Also, FIV cats should never be housed with FeLV cats, since their immune system is already compromised by their FIV infection, and will be more susceptible to the FeLV virus, even if vaccinated.
In contrast, you probably can keep FIV positive cats with FIV negative ones providing that the cats are not fighting, all are spayed or neutered, and that you avoid introducing any new cats that might upset the “peaceful coexistence” of the cats in the colony. Though a vaccine for FIV is on the market, this disease is terribly difficult to immunize against and protection is very uncertain at best. Look at it this way, if making a vaccine against FIV was easy and effective, we would already have a good vaccine for humans against HIV, and clearly, we don’t have one like that. With our current state of knowledge, the disease is just too complex to be able to make a vaccine that is very effective. For this reason, vaccinating FIV negative cats in order to prevent spread isn’t terribly effective.
For cats with either infection, a healthy and clean environment with good nutrition, good sanitation, and minimal stress is essential to provide the infected cats with the best chance of health and survival, and the uninfected ones with the best chance of avoiding infection.
And certainly, if you are caring for a cat with either FIV or FeLV, you should make every effort to prevent that cat from roaming. The more random contact the cat has with other cats, the more likelihood of a fight, transmission of one (or both) of the diseases, and usually a cat bite abscess.
*Conversely, for cats that test positive for these diseases that are unhealthy, and showing symptoms of severe infections, euthanization should be considered to alleviate their suffering.