Q. I have two house cats. When I rescued them as kittens almost five years ago there was a third sibling that tested positive for the feline AIDS virus. That cat has been living happily at my office, but I might not be able to continue keeping her there. How dangerous would it be for them to commingle? I’m especially concerned because I had the house cats declawed. (I’d never do it again.)

Wow, that’s a messy situation, isn’t it? But don’t despair; there’s always a solution.

First off, don’t worry about the claw vs. no-claw thing because that’s not how FIV is transmitted. Among spayed and neutered cats, bite wounds are the culprit. Above all, do not declaw your office cat; that would be terrible at her age.

Get all three re-tested for FIV. If they were only tested once at 11 weeks, it’s possible your office cat is not truly FIV positive.

If she tests positive again try, to find her a loving indoor home in an FIV-positive or single-cat household.

Failing that, you can commingle your three cats as long as you understand that transmission is possible. Most house mates, however, won’t bite one another, especially once you get past the stressful introductory period.

Here are tips on bringing a new cat to a household with established felines:

Make it gradual: The newcomer should spend at least one week behind closed doors so the cats can smell and hear — but not see — one another.

Follow this by a period of visual contact — through a screen or glass door, perhaps. Finally, if no aggression is apparent, move to well-supervised, in-the-same-space interaction.

Using a feline pheromone diffuser (like Feliway) during this critical period can help lower everybody’s stress level.

Whatever you do, be patient. It can take eight to 12 months for complete acclimation among cats — even siblings.

Dr. Patty Khuly has a veterinary practice in South Miami and blogs at www.dolittler.com. Send questions to khulyp@bellsouth.net, or Dr. Dolittler, Tropical Life, The Miami Herald, 1 Herald Plaza, Miami, FL 33132.