This article is about comparing the life expectancy of cats with FeLV compared to those with FIV. There are no clean, black and white answers which is disappointing for me because I like to provide clean answers.
FeLV life expectancy
You probably know that the Cornell Feline Health Center at the Cornell University College of Veterinary Medicine states that the “median survival time for cats after FeLV is diagnosed is 2.5 years”. The word “median” means the midpoint of those with a shortened lifespan and those with longer lifespans. This is compared to the ‘average’ which is adding up all the lifespans and dividing that number by the number of cats.
A median life expectancy is not that useful. Cats who are healthy but FeLV-positive “can live long, full lives in many cases” (Cat Owner’s Home Veterinary Handbook). They’ll need excellent care including top quality nutrition and minimal stress.
And about a third of cats with FeLV develop a virus-related cancer. These cancers cannot be cured. FeLV-positive cats with associated cancer have an average survival time of only six months even with the best treatment according to my research.
You can see the difference between the six-month survival rate of those cats who develop cancer and the median lifespan of 2.5 years. This gives you a feeling for the percentage of cats that develop a cancer-related illness.
FIV life expectancy
Once again, it is tricky to work out the life expectancy of a cat with FIV. For instance, Google’s top search result on this topic comes from the Animal Hospital of Pensacola, USA. The authors of that article states that a cat can live for an average of five additional years after contracting FIV. It depends upon how active the infection is.
This doesn’t provide the full answer because it doesn’t tell us the average age at which a cat might contract FIV. The incident rate of FIV is highest in outdoor cats and in males between 3-5 years of age.
Cat advocates insist that cats with FIV can live full, healthy lives and no doubt that is true. It is also true that some have shortened lifespans.
To try and work out an average is perhaps pointless. I tried this years ago and came up with an average lifespan of FIV cats of about 0.7-0.8 (70%-80%) that of healthy cats. I decided that taking all FIV cats together on average they will live to about 12-14 years of age. That may be entirely incorrect, but it was my attempt at trying to answer the question.
There is an extensive range of treatments nowadays for FIV cats including medications to prevent secondary infections, electrolyte and fluid therapy, parasite control, drugs to boost the immune system, drugs to reduce inflammation and a specialist diet.
There is no effective treatment for the FIV virus. Essentially the quality of care should be very high, and the cats should be kept indoors and stress minimised. Your vet will provide the best advice on this.
Please share your first-hand experience.