Dear Michelle L.: There is no point (and much risk) in vaccinating an immune-compromised cat who is FIV+ or FeLV+. Vaccinations are an assault of sorts to the immune system and can be detrimental to even a cat with a normal immune system. There is much good info about the risks of vaccines on the website Holisticat.com, or I would recommend highly the book by Dr. Martin Goldstein, The Nature of Animal Healing.
Some vets do still believe that the FIV and FeLV viruses are related, but more recent research tends to show they are not just substrains of the same virus. The best that we can do for immune-compromised cats is to provide them with the healthiest possible diet, provide immune support and protect them from exposure as best we can to undue stress to their immune system due to emotional challenges, enviromental toxins or other cats that may carry pathogens that their immune system cannot withstand. Other cats are really more of a threat to the FIV+ or FeLV+ cat than vice versa. I have not done much research on FIV, but got a crash course on FeLV in '03-04 with two unrelated kittens I rescued in Oct. and Nov. '02 who turned out to be FeLV+. The strain of FeLV virus (call it FeLV-A) that cats pass one to another causes significant immune suppression, but little else. It is through recombining with a cat's DNA and mutating that the more virulent subgroups occur, the FeLV-A+B that is associated with lymphoma or other cancers and FeLV-A+C that is associated with nonregenerative anemia/leukemia. In the worse case scenario it is possible for both subgroups to develop to FeLV-A+B+C. At present the mechanism which prompts such mutations is not known. This explains why some cats live for years, even with the virus in their bone marrow, while others crash and succumb early on. Have you found out there is a similar progression for cats who are FIV+? In general, they seem to have a better prognosis for long-term survival than do FeLV+ cats and I have always wondered if there is any research out there to suggest why this may be the case. I also wonder if the concept of viral load is a pertinent one with FIV and FeLV, as it is where corona viruses like Panleukopenia and FIP are concerned. Since your three cats have already been together long-term, unless they are hostile toward each other and prone to fighting, I would not separate them but just keep the stress in their lives as minimal as possible, provide a healthy natural diet with immune support and supplements to address any symptoms they may have. And, of course, LOVE them one day at a time. I would NOT vaccinate them for FeLV or FIV, respectively. The FeLV vaccine has been implicated in causing a latent infection to become an active one. Most holistic vets whose books I've read do not consider the FIV vaccine to be safe, either. Sally in San Jose
