Is there any way to find out how the kitty does with other cats? I mean, that is the primary concern... some shelter have a "cat room" that they allow their vaccinated cats to live in. I have found that my older females get along best with the new intro cat being a male. Don't ask me why- my vet suggested it and it has always proven true! Maybe hormone smell? Maybe my perception only! Of course, my older single female was a "nasty" (hit other cats) gal so maybe that had something to do with it? Just follow the "rules" for introductions and I'm sure all will be ok. You know, separate rooms at first, smelling under the door (moosmom uses a shirt with new cats smell on it and vice versa to get other cats used to it during this period) Actually- she would be a good person to consult! Then put new cat in carrier and let your cat sniff around, let them spit for a bit then back to room, do this a few times, then face to face with water sprayer ready to separate in case of an all out fight (not if just little tapping stuff though). This could take how ever long it takes them to get used to each other, and it means being patient. Which obviously you already are! Keep us updated and pictures!