A strain of FIV very similar to HIV humans is relatively common amongst outdoor cats with some estimates being that as many as 4-5% worldwide having FIV antibodies. Transmission is through bites and scratches rather than being sexual. Two important facts though. First this disease cannot be transmitted to humans. Second it will not necessarily shorten the life of the cat.
In a recent article Do Cats With FIV Foretell HIV’s Future? Ricki Lewis, who has a professional background in genetics and also experience of keeping two FIV positive cats, explains why veterinarians often fail to mention the need to vaccinate a cat against FIV:
#1 Logic. Cats most likely to be infected with FIV are outdoor males. “FIV is a disease of young cats with outdoor exposure. That’s the segment of the cat population that should be vaccinated,” explained Arne Zislin, a veterinarian and Technology Manager, Pet Marketing for Boehringer Ingelheim, which produces the vaccine. It’s considered a “core vaccine“ for this group of felines. A captured cat, or pet that goes outdoors, would have an initial vaccine, then yearly boosters, and get a microchip (more on that below), he added. But the homeless outdoor cats are the hardest to catch, says my friend the vet from Texas [...]
#2 An indoor cat wouldn’t need the vaccine. “The chances of a household cat being infected with FIV is virtually nil, and even the chances of a neutered cat allowed outdoors from time-to-time becoming infected is also extremely low. Many FIV-infected pet cats live comfortable lives among non-FIV infected pet cats with a very low risk of passing the infection,” Niels Pedersen, DVM, PhD, director of the Center for Companion Animal Health at the University of California, Davis and co-inventor of the vaccine, told me.
#3 Practicality: Neither Dr. Bart nor my vet friend sees enough FIV-positive cats to justify vaccination. “I go through all my feline leukemia virus vaccine, but have thrown away trays of FIV because it has expired…you do that a few times and it makes you re-evaluate the need,” said TexVet.
#4 Insufficient protection: Like flu vaccine, FIV vaccine only protects against some viral strains. What worked in California in 2002 when the vaccine came on the market might not work in New York, and doesn’t cover my Texas friend’s cat population. Three doses of the vaccine, according to some studies, provide a 0-80% protection rate – too much of a swing for many vets.
#5 Mistaken euthanasia at shelters. An FIV-vaccinated cat makes antibodies against the virus for the rest of its life – as does an infected cat, even one without symptoms. “If you vaccinate a cat it will confound the typical test in a veterinary hospital to determine if a cat has FIV,” said Dr. Zislin. Shelters have euthanized pets testing positive from vaccination.
This is all very interesting and some assurance that an FIV vaccine is not worthwhile for the majority of cats. Most fascinating of all is the experience that Ricki Lewis has of keeping FIV positive cats. Though her cats Juice and Artie have had periods of illness they have pulled through. They have lived with other cats without infecting them. Most important of all have been amazing companions and are likely to have many more years to live she believes.
Have you ever thought of adopting an FIV positive cat? If this thought even fleetingly occurs to you then you must read Ricki’s uplifting article My Cat Has Aids. Best wishes to Juice and Artie, may you have many more happy years ahead.