How To Successfully Introduce Cats: The Ultimate Guide

Feb 14, 2015 · Updated Sep 22, 2016 · ·
  1. Anne
    Many of our members will tell you that "one cat just leads to another", and that "cats are like chips, you can't just stop at one".

    People get a second (or third, or fourth...) cat for many reasons. Cat lovers cherish the thought of having yet another feline in their lives; they may want to provide their resident cat with companionship; sometimes the new cat just adopts them. Whatever the reason, the new cat needs to be introduced into your household and to your resident cat or cats.

    Cat introductions are always a challenge. Cats are territorial by nature and an intruder in their territory will stress them out. Some cats will hide away in fear but most will respond by attacking the newcomer. Both cats will suffer from the interaction and you will find it extremely difficult to have them live together peacefully in the future. Moreover, territorial stress as a result of poor introductions can cause other behavioral problems such as re-directed aggression, litterbox avoidance and territorial spraying. The conclusion is simple:

    If you bring home a new cat make the introductions properly.

    Don't just place the two cats in the same room and expect them to be friends. It is up to you to conduct the process in a very gradual and patient manner to get the desired results.

    Setting the Expectations

    Speaking of desired results, we all want our cats to be best friends. When bringing in a new cat, especially when the motivation is to provide the resident cat with a companion, most owners visualize something like this -

    It certainly can happen. However, it doesn't have to. Sometimes, even with the best of introductions, cats just don't like each other. Just like humans, they have their own personalities and temperament which do not always match up. Imagine if someone brought a stranger to live with you. It's possible that you'll become best friends, but it's also entirely possible that you never will. You may just not be a good match for each other. The best you can hope for in such cases, with humans, or cats, is to avoid fights and aggressive behavior and for both cats to tolerate each other's presence, at least most of the time.

    You can increase the chances of finding a good feline friend for your resident cat by trying to find the right match for him or her. Read more about choosing the right cat and remember to keep your expectations reasonable.

    Before We Start

    Before any introductions can begin you have to bring home the new cat. That's not as simple as it may sound. You need to prepare a sanctuary room where the new cat can spend the first few weeks in peace, away from the resident cats. Read more about bringing home a new cat and follow the advice given for setting up the newcomer's room.

    Make sure both cats are healthy and free of parasites before introducing them to each other. The new cat should be seen by a vet and infectious diseases need to be ruled out before you bring him or her home.

    Give the new cat a few days to settle in. The move itself created plenty of stress as it is, so there's no need to add the stress of introduction sessions at this point. That said, be aware that the introduction process has in fact begun. The cats will smell each other off you and possibly through the closed door. If one of the cats is vocal, that's another way for them to learn about each other's existence. That's fine for now but don't try to bring them together just yet. Wait for the new cat to adjust to his or her new surroundings first.

    During these first days, make sure you bond with the new cat, but don't neglect the resident cat. There is no need to comfort the resident cat, just keep up with your regular routine of food, treats and playtime. Be calm and casual and don't be alarmed if the resident cat hangs around the door of the newcomer's room, possibly displaying signs of aggression. It's perfectly natural. Just make sure he or she doesn't get into the room by accident as you step in and out.

    The Key Principles of Cat Introductions:

    Desensitization through Gradual Exposure and Positive Association

    There are many techniques for introducing cats. They are all based on the same principle:


    the cats to each other's presence so they no longer feel threatened.

    This is achieved by -

    1. Making the exposure gradual.

    Gradual exposure decreases the cat's "fight or flight" responses in the presence of an intruder, to the point that it is no longer triggered and he or she can learn to accept the presence of another cat in their territory.

    2. Creating positive associations.

    Many techniques rely on distracting the cat with positive stimuli while in the presence of the other cat. This creates a positive association with the other cat, reducing aggression levels.

    While on the subject of positive associations: Make sure you don't end up creating any negative associations during the introduction process. No matter what the cats do, or how the process goes, keep your tone of voice calm and avoid scaring the cats in any way.

    Introduction Techniques

    The following techniques utilize at least one of the principles detailed above and sometimes both.

    1. Scent Desensitization

    Scent is central to your cat's perception of the world. Take a clean sock and put it on your hand, then pet the new cat with your sock-clad hand. Focus on rubbing the cat's face, chin and cheeks. You are in fact lacing the sock with the scent of that cat. Next, leave the newcomer's room and return to your resident cat's "territory". Place the sock within the cat's reach. Don't call the cat over or initiate any interaction with the sock. Allow the resident cat time to find the sock and investigate the new smell. He or she may react with fear or aggression. Just let the cat be and make sure the environment around them is calm (yourself included!)

    Do the same thing with the opposite setup. Use a clean sock (not the same one!) to soak up scent from the resident cat, and place that sock in the newcomer's room. Repeat this once a day for several days, until you see a reduction in both cats' reactions to the socks. If your cat is a fan of treats, you could try and offer one as she's sniffing the sock to create a positive association with the scent.

    2. Visual Desensitization

    Once both cats are desensitized to scents, you can move on to the next sense: vision. The challenge here is to allow the cats to view each other, without letting them engage in direct physical contact. Cat behaviorist Pam Johnson-Bennett suggests using three baby gates, one on top of the other, to create a gate the size of your door which you can use as an additional door to the new cat's room. A screen door works too. Behaviorist Jackson Galaxy suggests sticking with the regular door and just opening it up a crack, allowing the cats to view each other in a controlled way.

    Allow the two cats to see each other. Don't be alarmed if they show aggression, and stay calm. You can use treats to make the session more pleasant. Jackson Galaxy even suggests feeding the cats when in this situation. According to his method, you should limit feeding to the times when the cats see each other through the crack in the door, placing their food dishes far away at first, and bringing the dishes closer every day.

    3. Interactive Playtime & Treats

    You can vary introduction techniques a little bit, and change them based on what you know about your own cats. Some cats couldn't care less about food or treats when they see another cat and may prefer playtime instead. Remember the principles behind the techniques and you should be ok. If need be, create the positive association by interactive playtime with your cat. Read more on how to conduct playtime sessions with your cat.

    Keep in mind that some cats may be extremely tense in the presence of a cat they don't know or trust. Whether playing or providing treats, stay in control of the interaction and don't allow them to come into physical contact too soon. Watch out for re-directed aggression as well. A cat may become all worked up over the other cat's presence and lash out at you with no warning. When playing during introduction sessions, keep your hands out of reach and use only fishing-rod toys.

    How Long Should This Take?

    It really is hard to predict. A lot depends on both cats' temperaments. Generally speaking, it's much easier to introduce kittens to each other than adult cats. Some adult cats are very cat-friendly and will gladly accept the company of a new cat. Others may always prefer to be the only cat in the house and never fully accept another cat's presence.

    As you move forward with introductions, watch the cats' body language and try to assess their cues. Don't move forward before both cats are calm. It's better to take a few more days before moving on to the next stage than risk a cat fight.

    Comments? Leave them using the form below. Questions? Please use the cat forums for those!

    Share This Article


To make a comment simply sign up and become a member!
  1. Dwell
    I brought in a stray that I've been taking care of at work. He's fine with me but I have 3 other cats and he got past me after a couple days and went straight after my male cat. I grabbed him and he bit into my arm that ended up with a trip to the ER. Two days later he got past me again (Totally my fault) trying to do two things at once. He went straight for the female sitting in the dining room and ended up biting her. This time I brought them up but didn't make the mistake of grabbing him. I just stood in front of him until he calmed down and was able to pick him up and put him back in his room. It's been about two weeks now and the female is healing from her wound thanks to vet and $220.00 later. I was going to take him to a friends house who has two small dogs but I'm afraid either he'll go straight for the dogs or the mean little dog will go after him. Or he will bolt out the door when my friend lets his dogs out to pee. So, I have decided to try again and see if I can get this to work. I'm going to cut a hole in the bed room door and install a screen guard so the cats can see each other without the chance of getting at each other. (More concerned about the new cat than my cats as he's been in the wild and probably had to fight other cats or racccoons and such) I'm hoping this with eventually work. I've spent 3 months feeding this story and I made him a shelter for the extremely cold nights and had him FIV tested and neutered. (another $300.00) I'm not worried about the money, I've just grown really fond of this cat and spent a lot of time getting him to this stage I feel I can give it some more time to see if I can make this work. I've read a ton of articles but any suggestions are greatly appreciated.

  2. Salios
    I'm just introducing a new cat today and aside from two mishaps when the new girl slipped past me into my bedroom with my older girl, they've been separated. My old cat is my support animal but she's used to a house with three people and a dog. Single apartment life has been stressing her out.
    I'm going to give this a go, but the yowling is a bit to get used old girl is taking it like a champ. 10 years old and couldn't give less of a shit.

  3. biscuchu321
    I have two adult cats at the moment, brother and sister, (they haven't had kittens) and I want to introduce a kitten to them. We're moving house, so I think it would be much easier to introduce them because they haven't set "territories" yet. My female cat loves to play, and has a kind personality, yet quite jumpy, and my male cat is more of a chill personality, and doesn't usually find playing entertaining. He also has a short temper, and he only likes me. Do you think they'd accespt the new kitten in this situation?
  4. gabriele33
    I have had cats with me for over forty years and have never yet introduced a new cat to the older one the way you describe. I have always just given them the freedom of the house and they have always become friends. They have all been females. Maybe it's different for males? Gabriele