Advice on Integrating Cats Into a New Household

I realize you want to avoid as much bloodshed as possible during the integration process, but its just not 100% possible. Resign yourself to the fact that there will be bad language (probably both yours AND the cats'), there will be fur lost and they will fight. Of course, try to minimize this. I've had luck with letting them get to know each other on opposite sides of a sturdy baby gate. Or maybe just under the door. Don't play favorites, give both sides the chance to be the "home team". And you'll probably have to deal with territorial spraying/peeing. I gave up trying to wash the curtains every time somebody peed on them to stake a new claim...I took the curtains down and draped sheets over the windows. Much easier to wash. Let them work out their new family order, even though it will involve some tense standoffs. We have a family of 9 cats and a dog, and we all understand that it is necessary to not kill each other. I can't say we don't have cussing and hissing, because we occasionally do still have moments of disagreement. But its not often, and when I holler THATS ENOUGH!, everyone quiets down for the most part. Be firm, be equal and be loving. And best of luck.

Jackson Galaxy has excellent advice on his webpage about integrating new cats into a household. I've done it many times, and while there are always fireworks, it can be done. The most important thing (and you've done this already) is not to just bring them together all at once. It needs to be a gradual introduction, with chances for them to smell each other without being in the same room. The last couple of times I've kept the newcomer in the bathroom but after a couple of days, let her out into the bedroom during the day, where she can smell where the others have been, and they can smell where she's been after I put her back in the bathroom at night.

Jackson also recommends introducing them on either side of a cracked door with something they find pleasant--feeding them, e.g.

It will take patience on your part, and it's important to remember that eventually, they will have to work it out themselves. I admit I've been astonished by some of the friendships that have eventually formed between a longtimer and a newbie. I've also been astonished by how long it took before one of my cats would stop menacing and harassing the newbie. My record for a smooth introduction was 3 days (the newbie was a kitten) and the record length of time it took before the growling and hissing stopped was 3 months. Just depends on the cats.