Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV)

Most commonly referred to as FIV and FeLV (or Feline AIDS and Feline Leukemia), Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) are both specific to the feline population. They can not be transmitted to people, dogs, or any species other than cats. Both are typically transmitted via blood-to-blood contact, or saliva-to-blood. The most common methods of transmission are fighting and mating. For this reason, the majority of cats who are spayed or neutered will not transmit the virus.

Both viruses are considered "retroviruses". There are more than just two retroviruses, but all retroviruses produce an enzyme called reverse transcriptase, which permits them to insert copies of their own genetic material into that of the cells they have infected. Although related, FeLV and FIV differ in many ways. The two viruses are quite different genetically, and their protein constituents are dissimilar in size and composition. Although many of the diseases caused by FeLV and FIV are similar, the specific ways in which they are caused differs.

FIV is very similar to HIV, in that the cat may harbor the virus for many years before showing any signs of the disease. A cat with FIV commonly has a lifespan as long as an FIV negative cat, especially if it is an indoor pet with no exposure to other infections. When infection does lead to a state of immune deficiency that hinders the cat's ability to protect itself against other infections, the same bacteria, viruses, protozoa, and fungi that may be found in the everyday environment--where they usually do not affect healthy animals--can cause severe illness in those with weakened immune systems. These secondary infections are responsible for many of the diseases associated with FIV.

FeLV is more likely to develop than FIV, and is likely to develop at an earlier age. However, FeLV can also be managed to give cats long healthy lives. FeLV is the most common cause of cancer in cats. It may cause various blood disorders, and it may lead to a state of immune deficiency similar to that described above for FIV. Once this state of immune deficiency occurs, health may deteriorate rapidly.

Adopting a FIV+/FeLV+ Cat

Only Hope Cat Rescue, Inc. has some great FIV+ cats available for adoption. Unfortunately, FIV+ cats are usually overlooked because people don't know enough about them and are afraid of taking in a "sick cat". Like HIV, FIV can remain "inactive" for years, and it's common for cats to live a full lifespan without exhibiting signs of the virus. FeLV is similar, but can begin earlier and be a more difficult illness than FIV. NEITHER virus is transmittable to people, dogs, or other species - but it IS transmittable to other cats. For this reason, FIV and FeLV cats can not go into homes with cats who have tested negative for these viruses.

As any of our adopters can tell you, Only Hope is EXTREMELY supportive of our adopters. We receive calls years after the initial adoption, from people looking for our advice or assistance with an issue. We are so grateful that our adopters continue to look to us for support, and we are glad to be there. Anyone adopting an FIV cat, just like anyone adopting any other cat, can count on Only Hope to be there as a support network for them.


Back before Only Hope was established, one of our members came across a sweet little cat who needed help. She brought her into her home, and not really knowing anything about isolating cats, she still instinctively put her into a room separate from her own two cats. She named the adorable little tuxedo cat Pickles. When she took Pickles to a local vet, Pickles was tested for FIV and FeLV. Unfortunately, she tested positive for Feline Leukemia. The vet wanted to euthanize her! The woman had to fight to get this affectionate, vulnerable little cat out of there. She sat in the waiting room, calling every and any rescue and shelter that she could get advice from. She finally found someone who told her what she needed to hear - that Pickles could live a healthy life and not infect other cats if she was kept away from them. So she took Pickles home and kept her in a room in her home for a year, before she found someone willing to adopt her. Six years later, Kris still pet-sits for Pickles and visits with her Daddy, and Pickles is in fantastic health! Her indoor-only status and quality diet have done an amazing job of keeping her in good health.

We are hoping that you will add to our FIV/FeLV success stories section by adopting one of our positive cats.