Prevalence of FeLV and FIV

Here is some data on the prevalence of two well known diseases in cats that were domestic and feral: FeLV (Feline leukemia virus) and FIV (Feline immunodeficiency virus).  There is a comparison in some rows between domestic and feral cats in the table.

Place	FeLV	FIV
Animal shelter, Birmingham, England - 1997	2% feral cats and 3.6% tame cats	20.4% feral cats and 9.4% tame cats
Vets - Istanbul, Turkey	6% outdoor cats and 5% for indoor cats	22% for both indoor cats and outdoor/feral cats
Texas University, USA	5% of cats trapped	6% of cats trapped
Florida University, USA	7% of cats	7% of cats
North Carolina Uni	4% of cats	4% of cats
Prince Edward Island, Canada	5% of trapped cats	6% of trapped cats

Some added information:

• In Istanbul, FIV was more common in male cats probably because they were not neutered. 
• In the Florida and Carolina and Prince Edward Island studies FIV was more prevalent in male cats.
• An interesting conclusion was that in colonies where TNR is practised the prevalence of FeLV and FIV was found to be low. Conclusion: TNR managed sites are a limited or low threat to the health of other cats.
• The university programs in the USA relate to trapped cats. These were therefore feral or stray cats.

Source: The Welfare of Cats edited by Irene Rochlitz:


This is a very good book. Scientific, yes but sound.