One cat is great, so more cats are obviously better, right? Even if you have generally very sweet, friendly cats toward you or other cats, you need to do a careful introduction. Cats are extremely territorial so cat introductions can be tough. A new cat in their space that they are not familiar with can make even sweet cats become not so sweet.
I’m covering the basic steps to help you give your cats the best chance of living in harmony (or at least tolerating each other), but every situation is different. You may need to do additional steps or some steps may not be needed. If you want more specific advice, I’m happy to set up a consultation to help you figure out how to introduce your cats.
Realistic Expectations
Before going any further, make sure your expectations for a normal cat introduction are in line with reality so you are less likely to make mistakes. Some cats may quickly take to each other, but that’s not the norm if you’re introducing adult cats or there is a large age gap. Your top priority is helping the cats feel safe around each other. Feeling safe is more important than them having a positive association with each other.
In many cases, this process takes weeks or months. You shouldn’t feel bad if you’re still working on this three months in because this isn’t an easy thing to do. You have to go at the speed of your cats because if you try to rush things, it’s less likely to work out.
In some cases, the cats won’t be a good match. While you shouldn’t adopt a cat with the expectation of rehoming them, if it means your resident cats and the new comer don’t live in misery? Rehoming may be the kindest choice.
Before The New Cat Arrives
In order to get your new cat adjusted to their new home, they will need their own separate space that your resident cats won’t have access to. Usually this will be a separate room, but work with the space you have. If you happen to have a large home so the cats can have separate floors to themselves, that works great! Regardless of what you specifically use, set up the newcomer’s kingdom before they arrive so you can minimize changes later.
The new cat’s space should be quiet, a comfortable temperature, and somewhere you are comfortable spending time in. It shouldn’t have any dangerous objects, including plants you don’t want the cat munching on or anything that could injure the new cat.
Things To Get
Set up the space to make sure all your cat’s basic needs are met in the room. These needs include:
- An appropriate litter box
- Food and water/a water fountain (placed separately from the litter box)
- Scratching post
- Bedding
- A hiding place or places
- Toys
- Somewhere to climb
If you need a few ideas of things to grab, check out my suggested products page or Amazon storefront.
Things You’ll Need Later
While you won’t need it immediately, you’ll eventually need a way to have the cats see each other without being in the same space. I don’t recommend using carriers, kennels, harnesses, or any similar item for this. Your best choice is a full door height pet gate.
While they generally aren’t inexpensive, they will make your life so much easier. They’re harder to jump than normal sized baby gates, can be left up (and covered so your cats can’t see each other… more on that in a moment) between sessions, and can be moved later in the process.
If you want one that gives a lot of flexibility, check out this full door gate that can have the height and width adjusted.
Make Environmental Changes Ahead Of Time
Once you have all the things you need for the new cat, you can start making changes to your home. At least a few days (or longer if your cats will be particularly distressed by closed doors) ahead of bringing the new cat home, close the door to their sanctuary room. This will help your resident cats get used to not having access to it. Use this time to make any changes you need to the main living space so there aren’t too many changes for them.
It also is a great opportunity to add in additional cat things for your resident cats in the main living space. This serves two purposes:
- It helps them not feel like they are losing territory.
- It ensures you have enough cat things and resources for all your cats.
You want more of most resources than you do cats so they always have a choice in where they spend their time doing their important cat duties. This is particularly true for litter boxes! A good rule of thumb for all resources is one item per cat plus one extra and at least one on each floor of the house. Everything should be spread out so it seems to your cats like you have more things than you do.
One potential exception to this is feeding locations: you can probably just have one per cat, but they should be spread out so your cats don’t need to eat near each other.
Preparations For You and Your Resident Cats
Once your home is set up, you and your cats have some work to do before the new cats arrive!
Understand Body Language
If you aren’t familiar with cat body language, especially signals of tension between cats, start learning before the new cat comes home. It will be extremely important later in the introduction process to be able to understand how each cat is feeling. Kitty Language by Lili Chin is an easy-to-follow resource on how to tell how cats are feeling. You can also check out my cat body language video.
Scent Introductions
If possible, obtain something that smells like your new cat ahead such as a cat bed they snuggled into frequently to allow your cat to get used to the new cat’s scent. If you can leave something that smells like your cats (bedding or a towel works great) with the new cat, it will help them become familiar with your cats’ scent.
That said, one thing to avoid: rubbing an item on your cats. This may create more stress and you don’t want the cats associating each other with being stressed out. It’s also not necessary if you pick something the cat already left their scent on.
If your cats like catnip, silver vine, or valerian root, you can sprinkle some of them on the bedding with the scent of the new cat. This may help them feel better about the newcomer! If you’re not sure if your resident cats like them, try a blend with all three so you don’t need to guess.
Bringing The New Cat Home
Bringing home the new cat is when many people start making mistakes that create problems later. A few best practices to try:
- Bring your new cat home in their carrier and directly to their safe room. Do not try to carry the cat in without a carrier or let the cats see each other.
- Covering the carrier will help the new cat not see any other cats as you transport them.
- Introducing the cats in carriers is extremely scary. The cats in the carrier can’t get away from each other so they’ll be terrified. Your goal is to help the cats feel safe around each other.
- You can also temporarily distract the resident cats with a food puzzle or keep them in a separate room if needed.
- Block off under the door to the new cat’s safe room so they don’t see each other too early. A draft stopper usually works for most cats and is what I used when I introduced my cats.
Set the new cat’s carrier down in their room and allow them to decide if they want to get out or not. Never force a cat out of hiding as this will just make them more fearful. No need to do anything like showing your cat their litter box because your cat will explore as they feel safe.
They may run and hide or they may hiss at you. That’s okay! Let them settle in.
Exploring And Meeting You
Depending on how the new cat does, you may need to leave the cat alone in their room for a while to settle in. You can go in to give them food and check they have plenty of water. You can go in and sit quietly in the room, preferably on the floor or at the cat’s level, once they’re out from hiding. Don’t even think of forcing them out of hiding as that will make things worse. If you’re not sure if that’s happening, set up a security camera in the room so you can check on them remotely.
Let the cat come to you and initiate contact. You can offer a finger, but present it at a distance without shoving it in the cat’s face. The cat may sniff you, but be cautious about petting them right away. They should touch you first instead of the other way around. Start out petting only where they touch you and keep it short. Most cats prefer their cheeks and chin being petted so focus on those areas.
Over the next few days, spend time in the room with the cat. As they seem more confident, you can begin playing with them and interacting more and more.
Preparing For The Cats To Meet
While you let the new cat settle in, you can swap scents to help the cats build a colony scent (which is really important for cats getting along). This can be done by swapping bedding, but I really like swapping scratchers for this part. Cats have pheromones in their paws so when they scratch the same scratcher, they naturally mix scents. You can combine both scratching and bedding with a cat scratching bed that is easy to switch between groups of cats.
You can also take the lazy-but-still-effective approach by wearing the same clothing as you switch spaces and letting each cat rub against you. This serves essentially the same purpose as swapping bedding or scratchers.
Observe the cats’ reactions and do NOT move forward with the introduction if there are any negative reactions to the smell as it could signal a problem with the introduction.
Skip Feeding On Opposite Sides Of The Door
You may have heard the suggestion to have your cats eat on opposite sides of the door that separates them or a pet gate during the introduction process. This advice is an outdated method as cats don’t naturally eat in groups. Most of the time, they’re catching small prey that isn’t easily shared so eating near each other is aversive. You’re not actually building a positive association if the cats are stressed the whole time they’re eating.
Another problem? Cats will eat near each other unless extremely stressed. That doesn’t mean they like each other, feel safe, or will be fine meeting face to face. Eating is a basic need for survival so they may put up with being near a cat they aren’t comfortable with in order to eat. Food is very motivating!
Playing Together May Help
As an alternative, you can try creating fun, mutual play sessions with the cats to start lightly having them meet before they can fully see each other. This isn’t always needed so this an optional step. To do this:
- Keep the door blocked when not playing so you can monitor the reactions of the cats.
- Use wand toys or make a barbell toy for the cats to play with under the door by sticking them under the door gap. Don’t let the cats just swat at each others’ paws as it might not be friendly.
- Only start doing this once the cats are totally calm and the new cat is settled in. They will be able to see each other a little so this should be the last thing you do before continuing on.
- Keep sessions short and end them if you notice staring, hissing, growling, or other concerning body language. It’s better to end things early!
When To Move On To The Next Phase
Every cat is different and every pair of cats is very different. A confident cat may need less time in the safe room and a more timid cat may require longer. For the whole introduction process, you have to go at the speed of the cats (even if you would like to go faster).
This means listening to each cat individually if you have multiple cats to introduce. Don’t rush the process or you’ll have a group of very stressed out cats.
Location Swapping
Once the cats are completely calm at baseline, you can try temporarily heard the resident cat(s) into a separate room and allow your new cat out to explore the main living space room by room on their own. It’s less stressful to introduce a cat to a large space room by room. This helps the new cat get used to their new home and builds a colony scent.
Ideally, you’d have a separate safe room for your resident cats to go into while the newcomer explores the more neutral middle ground. If you can’t do this, you can swap your resident cats into the newcomer’s safe space without the cats seeing each other at all by temporarily keeping them in another room.
Don’t Make This Hard On Yourself
Regardless of how you swap the cats, there are three important details to this part that will make it way easier on you:
- Don’t use carriers to do the swap. It may make it more challenging to get your cats into the carrier later.
- Picking up your cat and fighting them to change locations will create problems. Make it fun to switch rooms! The location your cat is going to should be way more appealing than the silly room they were just in so they choose to change rooms.
- Give yourself extra time to swap out the cats so it’s not stressful. Don’t do it at a time where it will be rushed so you don’t have an escape or create a long term problem.
Consider Skipping Or Delaying This Step In Some Cases
If it isn’t possible to swap the cats without seeing each other, it may be best to just skip this step entirely. Eventually you can do “micro meeting” where they see each other briefly during a swap, but it’s probably too early at this point.
Starting the location swaps early in the process may also create stress for the newcomer. While I am not at all advocating for keeping them totally isolated or separated any longer than is necessary, once they’re out of their safe room they might want to spend all their time out and about. You may end up with a very upset cat! Waiting to do this while making sure they get plenty of attention, play, and have a really fun safe room with lots of interesting things until later in the process may end up being less stressful for them.
Keep The Play Coming Between Swaps
If you are doing location swaps now, continue to have the cats play with a toy under the door with the door still closed. If you want a creative way to do this, use a ball track for mutual play. You can also work on clicker training with your cats to prepare for the next part. I’m available for lessons on clicker training or you can get a clicker training kit to try on your own.
Introducing Cats Visually
The next phase is the longest and where most of the work is done: having the cats get used to seeing each other and feeling safe while there are the other cats around. To do this, you’ll have the cats see each other with a barrier between them that prevents them from physically being in the same space. This is where the tall pet gate mentioned earlier comes into play.
If you didn’t already get one, you can consider making your own gate. Otherwise, I strongly recommend going for a full door height gate even if your cat isn’t a leaper normally. That may change! Go for a gate that is at least 70 inches high if possible.
Brief Meetings
To have the cats get used to seeing each other, you will repeatedly have short meetings between the cats so they can see each other in a controlled way while feeling safe. The cats should have a barrier between them with one cat on each side. Each cat needs to be doing something during these meetings to start with, but you will eventually reduce the distractors.
The goal is to keep the cats feeling safe while seeing each other. While this is typically phrased as building a positive association, focus on helping each cat feel safe as that is more likely to result in success.
Over time, gradually increase the amount of time these meetings last as long as all cats are doing well. You need to stop each meeting before the cats become stressed and don’t increase the time they see each other if they’re not calm. Don’t go too fast or just throw the pet gate up so the cats can see each other more. If you just leave the gate up, you can’t cut off the interaction should either cat show signs of stress.
What To Have The Cats Do During Meetings
Your goal is to help each cat feel safe around the other cat(s). While this might involve building a positive association, it’s actually building the feeling of safety that matters most. Your cats can coexist and be happy if they feel safe. They don’t need to like each other.
While you won’t need to worry about this quite yet, play or positive reinforcement based training are better choices than feeding the cats near each other. Playing generally puts cats in a good mood and is something they would do with other cats. Plus, for younger cats, it helps them get out the seemingly endless energy they have so they’re less likely to annoy each other.
Training Is The Most Effective
Training your cats is probably the highest yield activity you can do during meetings. It has two big benefits:
- Your cats directly learn what to do around each other. As you repeat the training, they will be more likely to do the behaviors your want.
- Clicker training is very predictable and your cat has control of it. This helps cats feel safe. The real benefit of clicker training comes from the control and predictability it creates.
While randomly giving your cat treats isn’t a great idea, it is okay to use your cats’ favorite treats as a tool for training as part of the introduction process. The benefit isn’t because of the treats and the process of training helps mitigate some of the downsides of giving your cats treats in view of each other.
Details Matter For Visual Meetings
For this phase, you’ll end up as a client of mine if you’re not careful. I’m awesome and love helping people with their cats, but needing professional help introducing cats is not something most people want to do. Pay very close attention to the following:
- Distance between the cats: Keeping the cats as far apart as possible to start will be less stressful for the cats. Only let them get close to each other gradually and never lure them closer.
- Keep the cats busy: Your cats should always have something to do such as clicker training, a pattern game, or playing when they have visual access to each other. You may need to change what you do if either cat isn’t doing well.
- Treats can be given after a meeting: The key here is after a visual meeting (unless you’re doing clicker training). Ideally, give the treats where they can’t see each other. In my experience, this isn’t the most effective method so it should supplement other interventions.
- Keep meetings brief: It’s best to start out having the cats see each other for only a few seconds to gauge how they do. Increase slowly and steadily.
- Don’t get greedy: If you push your cat too far, it may sensitize them to each other so they’ll react more strongly the next time they see each other. Don’t try to get away with too much as it isn’t beneficial to do the steps unless your cats feel safe around each other.
- Stop if there is hissing, growling, staring, or any concerning body language: Your goal is to end the meeting before any of these occur. If it does, you need to call it off right away. The more negative interactions the cats have, the higher the risk their relationship will deteriorate. Contrary to popular belief, it’s not normal for cats to get in fights when they meet.
- Let your cats walk away: It’s okay if your cats walk away from each other. The ability to leave if they feel uncomfortable will help them self regulate and prevent them from feeling trapped. It helps the cats feel safe!
A Note On Hissing
Hissing is complicated because two seemingly opposite things are true at the same time: Hissing isn’t a good thing and shouldn’t be ignored. It’s also not necessarily abnormal to have some cat hissing at first. A few hisses doesn’t mean that things are hopeless. It should lessen over time, but it’s still a good idea to end the interaction early in the beginning so things don’t progress to a full cat fight.
You also don’t want to stop the hissing. It’s the cat communicating a boundary so the problem is the stressor, not the hissing.
Side note: I am continuing the guide with the assumption things are going well. At this point, you may want some help if the cats are not digging each other. It’s easier to prevent a negative association than it is to fix an introduction gone wrong.
Melting The Gate
Eventually, the cats need to be in the same room as each other. They’re ready to begin transitioning to being in the same space when the cats do not react to each other with the gate up for a significant amount of time. There’s not a magic amount of time that indicates they’re ready, but the longer the better. Once they can ignore each other, you can either have them meet without the gate or take the more cautious and better approach of transitioning the gate away. I call this “melting the gate” because you slowly remove the gate rather than make it go away suddenly.
During the part, there is a greater risk of a fight or injury because there won’t be as much stopping the cats from coming in direct contact. Always have a towel, flattened cardboard box, broom, or cushion nearby to gently separate the cats if needed.
A Word On Harnesses
Harnesses are sometimes recommended for this phase, but you should skip them in most cases. While harnesses can have their place in some very rare circumstances, you absolutely have to condition the cats to enjoy being in the harness first. They are only there as emergency backup because they don’t teach the cats what to do or help them with their emotions. The cat also may feel trapped and unable to leave if they want. Unless you plan to have your cats harnessed constantly, they’re not worth the effort for most cats.
Make Opening The Gate A Non-Event
To start removing the barrier between the cats, you need to make the gate, door, or other barrier opening not super exciting so they don’t feel the need to run through it. The easiest way to do this is to lightly mess with the latch and make quiet noise with the gate during your meetings. The cats may react at first, but it should lessen with time. They should also be easily redirected toward the training or play they’re enjoying.
Once they’re good at that, you can open the gate slightly. Pay attention to each cat as, once again, we want them to ignore the gate opening. After a few seconds, shut the gate. As the cats get used to the gate opening and don’t react, you can increase the distance it opens and leave it open slightly longer. Your goal is for the cats to not run through the gate so if you notice them becoming too distracted by it opening, close it.
Gradually Have The Cats Enter The Same Space
Next we need to get the cats in the same room for the first time. Rather than just removing the gate to let your cats in the same room, a more gradual approach works better at this point, too.
- Keep your cats distracted and really far apart at first. Have someone else open the gate very briefly and close it.
- Move the cats closer as they demonstrate with the behavior that they can handle the gate being open without bolting. Play is your best option for this part. I used two Cat Dancers when I was introducing Poutine and ‘Zac.
- Have one cat play their way through the door or open gate then back right away.
- Continue doing this until the cats are fully in the same room as each other but still far apart.
- Gradually increase the amount of time the cats are together with distraction and then gradually remove the structure and distraction.
You should continue to end sessions before the cats show signs of anxiety or stress. You’ll know the cats are ready to have more time with each other by how boring this process is. It shouldn’t be that exciting.
When To End Active Participation
As you feel comfortable, you can begin letting the cats have unstructured time together and eventually short unsupervised time together. Add this in only if there hasn’t been staring, growling, or hissing and the cats are ignoring each other. Your goal isn’t necessarily cats that want to be around each other constantly; it’s cats that don’t try to maul each other and feel safe.
Do I Have To Do This?
I mean, no, I’m not forcing you to. But…
This all seems like a lot of work and I won’t deny that it can be depending on your particular cats. Some cats may take a few days to adjust, but you should go into this expecting it to take significantly longer. It’s not abnormal for a cat introduction to take a few months. It also doesn’t need to involve a lot of hissing or stress for your cats.
In the end, introducing cats correctly is less work than trying to fix a cat introduction gone wrong. This process is way easier to do than a reintroduction! And seriously, if it seems like a lot of work, I’m happy to help you out.
I hope your new cat, resident cats, and all humans involved enjoy their new home together and you all have many years of happiness ahead!
