Physically, of course, FIV-positive cats can go outside. This is a moral question more than anything else. It’s a question about protecting other cats who are FIV-negative. If you let a FIV-positive cat go outside they may pass the disease to a FIV-negative cat. Although transmission isn’t that easy. Close or casual contact alone is not a major source of transmission. The virus is shed in saliva. Cat bites occurring during fights among male cats are a source of virus transmission.
It’s believed that FIV affects 2% to 4% of cats in the general population in America and the incidence is highest in outdoor cats and in male cats in the age bracket 3-5.
Cats Protection in the UK gives us the full picture. They agree that cats pick up the virus mainly through fighting by bite wounds and as a consequence they recommend that FIV-positive cats are kept indoors but allowed outside into an enclosure. They shouldn’t be allowed direct contact with FIV-negative cats
They do say, however, that most boarding catteries allow FIV-positive cats if they’re not showing signs of any other disease. This is because standard precautions will prevent transmission of the disease including using disinfectants which kill the virus. Cats in boarding catteries are held separately.
There is a danger, however, that a FIV-positive cat at a boarding cattery might receive a virus from one of the other cats because their immune systems are poor. The real danger for a FIV-positive cat as a boarding catteries is for the FIV-positive cat not the ones who are FIV-negative.
FIV-positive cats should be allowed to live out good lives. They make great companions. But veterinarians would say that the most effective way of preventing the disease is to keep cats from roaming and fighting with infected strays. This dramatically lowers the likelihood of infection.
FIV stands for feline immunodeficiency virus.