Expert: Jessica - 8/5/2011

Question
Hi, i read in your notes that you say Feline leukemia and Aids is contagious.
Could you please explain how this is ? i was aware the virus can be passed by deep bite wounds from one cat to another, and considering i have two rescue cats with one of these two conditions each among 7 other house cats, would like to know about them being contagious.Thanking you, Wendy.

Answer
Hi Wendy,

As you are aware, Feline Leukemia and Feline AIDS are two separate diseases, caused by two different viruses. Although they can cause similar symptoms, FIV (AIDS) is much more difficult to spread.

FIV is spread only through deep, penetrating bite wounds. Saliva (or blood) must be introduced directly into the bloodstream. It is the opinion of most that it is generally safe to keep FIV-infected cats along with negative cats together in a peaceful household. This is the opinion I personally hold. It could be possible that a bite could occur at any time, and the risk is always present that the disease could spread. However, most adult cats are resistant to the infection, and the risk of a significant bite is minimal in households where the cats get along and all cats are neutered.

Feline Leukemia, however, is more easily spread. It can be transmitted with a penetrating bite wound OR via oral route. If the cat ingests infected saliva or nasal secretions, this is another possible way of transmission. So cats who groom one another are at extremely high risk for infection. Those who share food and water are also at a lesser risk. It is the opinion of most, mine included, that it is not safe to keep positive along with negative cats together. Although many adult cats are resistant to this infection, it spreads much too easily. And while many cats can live long, healthy years with AIDS, this is not the case with the leukemia virus. My oldest AIDS patient lived to 17. My oldest leukemia patient lived to 7, and she was the oldest my vet practice had ever seen. The average is just 2-3 years old.

If you already have Leukemia positive cats, I would recommend isolating them, or at least vaccinating your others against the disease. I personally do have leukemia positive cats as well as negative ones, but they are kept completely separated at all times. There is no contact allowed. Years ago, when we found out one cat in the cattery had come in infected during the window period, we went through and tested them all, and it was found 1/3 had contracted it (proof of how infectious it is). I also have AIDS positive cats, who stay along with the healthy cats. This disease has never spread.

Hope that helps!

Jessica