Depending upon how reactive your resident cat is, you can also let him do some exploration of the sanctuary room. Put the newcomer in another room so she can explore safely (or place her in her carrier and put then put the carrier in another room) and then open the door to the sanctuary room so your resident kitty can check things out. Keep toys and treats handy for distraction. Whether to let your resident cat into the sanctuary room depends on how reactive he is so you’ll have to be the judge here. For some cats, the sanctuary room of an unfamiliar cat is too over-the-top. For other cats, it’s a chance to do a more in-depth scent investigation in a safe way.
Step Four: Peek-a-Boo Kitty
The next step involves opening the sanctuary room door just a crack during the feeding sessions. Feed the cats within sight of each other but far enough apart so they don’t feel threatened. Do short sessions where you’re offering a tiny amount of food and then close the sanctuary room door. It’s better to do several short sessions a day that end on a positive note rather than attempting one long session where someone’s tolerance is tested and a fight breaks out. If one cat routinely tries to bolt through the door, use a door stop to prevent the door from fully opening. You can also place a hook-and-eye closure on the door temporarily.
Step Five: Fully Opened Door
When do you move onto this step? That’s determined by your individual situation. There’s no set time limit on how long you should stay in one phase before entering the next. If your cats aren’t comfortable enough yet with eating on either side of the door when it’s cracked open then you aren’t ready to move onto to the fully opened door. Cat introductions shouldn’t be rushed. Take each phase slowly and watch your cats’ reactions to determine whether to move on.
When it comes time to open the sanctuary room door and you’re worried one cat may charge through or if one or both cats have already attempted that then you take an interim step by putting two or three baby gates across the entrance or install a temporary screen door (with secure pet screening). This will allow the cats to see each other without being able to charge. When the short feeding session is over, close the actual sanctuary room door again. You can even use just one baby gate during the feeding sessions if you’re standing by the door ready to close it in case the worst happens. Even though the cats could easily hop over the gate, it can become a psychological barrier — just enough of one to relax the cats so they’ll be comfortable to eat.