The average life expectancy of cats with FIV (feline immunodeficiency virus FIV+) is likely to be slightly less on average than for non-FIV cats (FIV- cats). There is no stated, statistical figure that I can rely on. But FIV+ cats can suffer from related infections which leads to the conclusion that some FIV cats may die sooner than if they did not have FIV. However many of these cats will achieve a normal life expectancy of around 18 years.
So what percentage of a normal cat life expectancy can a FIV cat achieve? I’ll have to guess. If there were statistics on the average lifespan of FIV cats compared to non-FIV cats, I’d expect the FIV cats to have a lifespan of around 90% of non-FIV cats. But this assessment might be controversial because:
Many studies indicate that FIV+ cats live as long as FIV- cats. And…FIV itself does not cause severe clinical signs and FIV infected cats live many years without health problems. (Hartman, Veterinary Immunology and Immunopathology 2011)
If we agree the average lifespan of the domestic cat is 18 years, I estimate the average life expectancy of FIV cats to be 16 years. The word ‘average’ is important. As mentioned this statement may be controversial. The point is that FIV cats are just as good as any other cat as a companion. People should not shun the idea of adopting a FIV+ cat because of their incurable condition.
As there are so many variables that it is probably foolhardy to try and answer the question in the title.
For example, if the FIV cat’s caretaker is excellent and provides care of the highest quality in terms of food, parasite control, minimising stress and keeping him indoors, he may well live a happy and contented life which is as long as any other cat.
Alternatively, a poorly cared for cat with FIV may suffer associated infections which are ignored and he may die as a consequence at a relatively young age.
You can’t really or realistically answer the question in a straightforward, simplistic way with a single average figure. This is why you won’t find statistics on the internet.
P.S. Humans with AIDS (the human equivalent to FIV) can expect to life as long as people without AIDS. This is because of modern treatments. However, in my view, treating cats with FIV is less well developed than for humans and therefore there is likely to be an impact on cat lifespan.
P.P.S. To those who might vehemently disagree with me: I am simply expressing my views on my website. I am entitled to do that. I’d welcome the views of others in comments.