If you adopt an adult cat and you already have adult cats living in your home, manage the introduction process carefully to avoid fighting and eventually achieve harmony. Remember that cats are territorial animals and most will reject newcomer cats with extreme drama and noise. Follow these steps when introducing an adult, tame adoptive house cat to your home cat tribe. Your goal is “100% safe acceptance,” no clumps of fur found anywhere, no wounds of any kind, no emergency trips to the vet! If your cats actually become friends who sleep side by side, consider yourself lucky; it doesn’t happen often.

Consider adopting a cat who has lived with other cats to minimize the amount of adjustment time and effort needed.

1. Create a private room for the new resident.

• Provide the shelter or current owner with two items of bedding (small blankets, towels, t-shirts) a day or two in advance of pickup, with a request that the bedding be placed in your new cat’s sleeping space as bedding. When you pick up your cat, pick up the  bedding too. Put the bedding in your cat’s travel crate.
• Purchase and feed (until the adjustment period ends) the same food your cat is accustomed to eating.
• Outfit the private room with a clean kitty litter box, a soft cat bed on top of a bed or chair, food and water dishes and toys. Put one item of bedding on the cat bed to provide a familiar scent.
• If your private room has been off-limits to your resident cats, bring their scent into the room. Leave a piece of bedding in your home for a few days where your resident cats like to sleep, so that the bedding can pick up their scents. Put the cat bedding on the floor on top of a vinyl boot tray on the floor of the private room. If your new cat urinates on it, remove it, but if not plan to leave it there for the duration of the introduction period.

2. Introduce your resident cats to the new cat’s scent.

• If possible, enclose your resident cats into a safe part of  your home for a few hours so the adjustment period begins with a period of quiet.
• Put the second item of bedding with your resident cats, on top of a vinyl boot tray on the floor, away from the litter box and the water dish. If one of them urinates on the bedding, remove it, but otherwise leave it in place for a few weeks.

3. Introduce your new cat to the private room while your resident cats are enclosed.

Then, with the private room door closed, open the travel crate and let out your new cat. Your cat might explore confidently or might hide under the nearest piece of furniture. That’s fine. Talk soothingly and pet your cat if you can.

• Put your cat in the litter box and on the soft bed if you can.
• Put out food and water as near the crack of the entry door as is practical.
• Leave the room and visit every hour or so to give affection and reassurance, but try to leave when he or she is occupied, not interacting with you.
• Release your cat tribe and be prepared for them to discover the new cat smell. They might crouch near the private room door. Vocalization may commence.

4. Change the mood from mad to glad.

Calmly accept your resident cats’ objections and tantrums. Your new cat will likely vocalize as well. This is normal behavior; expect it. Start a program of mood modification and continue it for at least a week or until all of the cats appear to be interacting mildly, but keep your new cat in the private room.

• Feed your cats near the entrance to the private room, and do the same for your new cat, so they associate good things in the presence of the other cat.
• Put stick and string/ribbon-like toys under the private room door to encourage play. Your goal is to get your new cat and one or more of your resident cats playing with the same toy if possible.

5. Introduce your new cat to the home while your resident cats are enclosed.

Bring your resident cats into your bedroom at night and close the door (bring in the litter box). Then open up the door to the private room at night, so your new cat can explore safely. Continue this for a week or more.

6. Introduce your resident cats to the new cat, one at a time.

After all of the cats appear to be reacting to each other with markedly less intensity, bring one cat at a time into the private room for a supervised introduction, or bring your new cat into another room with one of your resident cats. Expect some occasional vocal objections.

• Provide plenty of treats and toys to distract them and change the mood.
• Keep a spray bottle full of water at arm’s length to break up a fight. If a fight erupts, go back to the previous steps for another week or two.

7. Open the door to the private room.

Let your cats tell you when they are comfortable. After a few (or many) weeks of supervised interactions, your cats might be ready to mingle freely. Signs of acceptance include eating or playing in the same room; sleeping or resting nearby; lack of jealousy when another cat is being petted.

Leave the private room open and outfitted for your new cat for another month or more, before gradually moving the litter box and feeding station to their permanent places. The transition to a new feeding spot might occur before the litter box or the opposite might also happen! Your goal is “no accidents” and gradual movements of the litter box might be more acceptable to your new cat. Put the litter box outside the door to the private room and close the door before gradually moving the litter box elsewhere.

A final thought.

Remember, your new cat needs careful introductions to your dogs but also to other pets that might be considered prey, including birds, rabbits, hamsters, guinea pigs, rats, snakes, etc. Do your research before you bring your new cat home.