Dear Sinéad and Siouxsie,
I don't have any pets of my own but I volunteer at a local animal rescue league. Recently they had an outbreak of Feline Leukemia. I was wondering if you could fill me in on what Feline Leukemia does and its long-term effects.
Sinéad: Hi, Volunteer. We'd be glad to answer your question. But first, we'd both like to thank you and all the people who volunteer at animal shelters. We're so happy you all are willing to help our homeless animal friends find a safe place to live, and we have a lot of respect for you.
Siouxsie: We also suggest that you send money to your local animal shelters. Lots of money! And food and toys and goodies, too. And don't forget to go over there and volunteer your time. The cats and dogs need you.
Sinéad: Anyhow, on to the question at hand. We asked Mama to do some research about Feline Leukemia so we could answer your question. There's lots of information about Feline Leukemia (FeLV) on the Internet and in cat care books, and later in this column, we'll share some web sites Mama found.
JaneA: Feline Leukemia is a retrovirus. A retrovirus is a parasite at the genetic level--a DNA tapeworm, as one author calls it. It tricks DNA into copying it instead of the normal genetic material of the cell, and that's how the virus multiplies. It usually starts reproducing in a cat's lymph tissue, which is the cat's first line of immune defense. Some cats are able to mount a successful immune response against it and defeat the virus at this stage. In cats who don't successfully destroy the virus here, the virus will then move into the bone marrow where red and white blood cells are produced. It may stay latent in the marrow for many years. After that it will attack other tissues, harm cats' immune systems, and make them unable to fight off infections.
Siouxsie: Yuck! How is it transmitted? I don't want to get Feline Leukemia!
JaneA: It's usually transmitted by saliva, mucus, urine, feces and blood. This means mutual grooming and biting/fighting are the most likely methods of transmission, although sneezing, hissing, sharing food/water bowls and sharing litter boxes are also possible means of transmission. It is not, however, contagious to people or to other species of animals such as dogs! The FeLV virus also doesn't live long outside the cat's body.
Sinéad: What happens to cats who get FeLV?
JaneA: Well, that depends on the cat. First of all, sometimes a cat infected with the virus will fight it off, and nothing will happen. Sometimes a cat will become a carrier of the virus but not get sick. Sometimes, though, a cat will get sick immediately. If you test your cat for FeLV and the test is positive, you may choose to re-test later to see if the cat has successfully fought off the virus and become FeLV negative. It has been known to happen.
Siouxsie: There are Shots for FeLV, aren't there?
JaneA: Yes. There is a vaccine for FeLV, but many vets are not convinced that it is effective enough. It does prevent transmission of FeLV, but not at the same rate that other vaccines prevent other diseases. If your cat goes outdoors, I think you should definitely get it immunized against FeLV; some vets will agree that the shot isn't entirely necessary if your cats are indoor-only cats.
Sinéad: Do cats die of Leukemia right away?
JaneA: Many cats can live good quality lives even if they're FeLV-positive. Most cats who get FeLV go into the latent stage--the virus is in the cat's body, but it is not producing symptoms of disease--which can last anywhere from months to years. It's important for people who care for FeLV-positive cats to keep them away from other cats. FeLV-positive cats must be indoors-only cats! Also, make sure you minimize the stress in their lives. Stress has a harmful effect on the immune system, and in FeLV-positive cats, the immune system is already compromised.
Siouxsie: But if the cat has the virus, isn't it going to get sick sometime?
JaneA: The odds are good that eventually an FeLV-positive cat (that is, a cat who tested positive once and then at a retest three months later still tested positive) will start showing acute symptoms. Unfortunately, since FeLV is a retrovirus that attacks your cat's immune system, your cat can become ill from many things as a result. This makes looking for a "sure sign" very difficult. Often the immune system is weak so your cat will become chronically infected with certain conditions such as stomatitis, gingivitis, oral ulcers, abscesses and non-healing wounds of the skin, upper respiratory infections or feline infectious peritonitis (FIP). Some cats whose digestive tracts are affected have been described as staring at their food bowl seemingly unable to remember how to eat, or their breathing will be very difficult and loud. Basically, if your FeLV-positive cat shows chronic, peculiar and/or unhealthy behavior, take it to a vet to be examined, because the disease is probably becoming acute.
Sinéad: Wow, that sounds pretty awful. I hope Siouxsie and I never get Leukemia!
JaneA: I've had you both tested for FeLV and Feline Immunodeficiency Virus (FIV), and you're both clear. So don't worry, you're not coming down with Leukemia. I did find some resources on the Internet that have more information about Feline Leukemia for our readers, and here they are:
Sinéad: I like A Cat-Shaped Hole In My Heart, too. When Mama sings the songs, I sing along! So, Volunteer, I hope this helps you understand more about Feline Leukemia and its long-term effects on the cats at your shelter. Thanks so much for writing to us.
Got a question? Need some advice? E-mail Sinéad and Siouxsie at email@example.com. None of the advice in this column is meant to be a substitute for regular veterinary care.