How to introduce a new cat to your existing cats

Bringing a new cat home is fun, especially if there are already a few of them waiting for a buddy. Cats are social animals, but at the same time, they are extremely territorial and suspicious. In nature, cat colonies rarely accept newcomers. But it is workable at home in a controlled environment.

In this article, you are going to learn how to introduce a new cat to your home and existing cats. Whether you bring home an adult cat or a kitten, the basic principles remain the same.

Introducing two cats

You should, however, remember that this topic may also be covered, if not in a book, then in a long chapter of one for sure. You will be able to follow the steps described below, but bear in mind that some modifications may be necessary according to your particular situation.

NOTE: The same procedure can be applied in the case of two cats who already know each other but exhibit aggressive behavior towards each other. In such cases, however, the proceedings will be slower and your ability to adapt your actions to the situation will have a huge impact on whether the introduction is successful.

1. Set up a separate room for your new cat

This should be a room in which you can set up a secure and quiet environment for your new cat, separate from the rest of the house and your old cat or cats.

This room will reduce the amount of stress and new sights that your new cat is introduced to, will help you carry out the cat introductions gradually, and will give your new cat a safe place to retreat to while exploring the rest of the house.

You should be able to close the door to this room when necessary and not use it for at least several days. The family gathering room or room which provides access to other rooms is not a good choice for new cat introductions. Bathrooms are also not a very good choice because it is difficult to make them safe for cats, but it is still workable if there is no other choice.

Here is a list of things that you should provide in the initial room for your new cat:

  • Food. It’s advisable to use the same brand and type of food that your new cat was given in the previous home. This will not only lessen his stress, but will also help avoid gastrointestinal upset. A small amount of fresh food should be made available as your cat arrives. If your cat seems to like it, you can provide the food in two to three meals per day. Feeding your cat on a fixed meal schedule has many benefits, and it may play an important role during the introduction to your existing cat. Later, as your cat settles in, you can think of switching your cat to new cat food which is acceptable for you.
  • Water. It is essential to provide water at all times. Remember to replace the old water with fresh water at least daily. Place the water bowl some distance away from the food dish and the litter box.
  • Litter box. This should be accessible and appropriate for your cat’s age. If your new cat had a litter box in his previous home, it’s advisable to use the same type of litter in it. Later, as your cat settles in, you can gradually replace it with your preferred one.
  • Cat reaching upVertical territory. This is the most important confidence building tool you have. Provide your cat with at least one or two cat trees and access to a window sill or top of other pieces of furniture that are already present in the room.
  • Scratching posts or cat trees. These are necessary not only for saving your furniture, but also because scratching is essential for cats. It is used to sharpen the claws, provide a good stretching exercise and mark territory. You can’t, and you don’t need to train a cat not to scratch. Instead, you should always provide as many appropriate places for your cat to scratch as possible.
  • A place to sleep. This does not necessarily have to be a bed. If you have a cat tree, your cat already has a place to sleep, but you can definitely place a cat bed on an elevated surface. It would be helpful if your cat can have a blanket or bed from his previous home.
  • Toys. Toys are necessary for physical and mental stimulation. Solo play toys are usually toy mice and balls. But don’t buy the ones stuffed with catnip, because catnip is intended to make cats active, whereas during introductions you want them be less active. Don’t forget about the fishing pole-type toys for active playing with your cat, but never leave them accessible at all times. Interactive play will help you to build more trust with your new cat.
  • Pheromone plug-in diffuser (optional). Feliway can be helpful to reduce your new cat’s stress about changing homes, but if your cat reacts well, there is no need to introduce feliway. You can learn more about what pheromones are here.

2. Bring the new cat home

Once the room is set up, you are ready to bring the new cat home. Try to do so in a way that your other cats don’t notice you arriving. Use the back door or have someone distract them while you bring the carrier into the room you set up previously.

IMPORTANT: If unsure, have the cat checked with a veterinarian before arriving home. It would not be a good thing to bring in any contagious diseases that could spread to your existing cats.

Place the carrier on the floor, open the door and leave. It’s best to give your new cat some space and time. He does not know you very well and should initially be let to adapt to the new environment, before interacting with you.

Some supervision, though, is still necessary, especially if you bring home a kitten. You may either settle yourself at a low spot and remain quiet in a corner of a room or check occasionally whether your kitten is all right.

3. Give enough attention to your existing cats

Woman playing with a Siamese catAn important part of introducing a new cat is not letting your existing cats feel left out.

Try to provide at least the same (or slightly higher) amount of attention as before. On the other hand, don’t overdo it, because this may make your old cat feel like something is not right.

Playing, petting, brushing or just letting the cat sit in your lap or lie next to you are good. It’s also beneficial to have frequent short interactions rather than one or few longer ones.

4. Spend some time with the new cat, but don’t be intrusive

You may want to spend tons of time playing with and cuddling your new cat, but try to keep it minimal initially. Make sure you carry out basic maintenance activities such as cleaning the litter box, replacing food and water for the first few days and observing how the new cat reacts to your presence.

Observe how he or she reacts to your presence and modify the amount of communication accordingly. If your new cat initiates the interactions and comes to you, there is no need to walk away. Offer to play and feel free to continue if the new cat responds. However, you should be able to recognize signs of aggression and fear in cats to know when it’s a good time to back off, which is either stepping a few steps away or leaving the room.

5. Scent and territory exchanges

And finally, we get to the part where we actually talk how about how to introduce your cats to each other. But again, this should be done gradually.

If you have already spent some days getting your new cat accustomed to the new surroundings, it’s likely that both cats are already aware of each other’s existence. This is good, because it prepares them for the inevitable introduction. It’s similar to a scenario where you are given time to prepare a speech for an audience as opposed to a scenario where you are suddenly asked to speak on stage.

But still, before proceeding with introducing the cats face-to-face, there are some techniques that will let all the cats get to know each other through scent:

  • Feed the cats together with a closed door in between. It gives them time to get to know each other through scent and noises, as well as acts as a positive setup for the introduction. You can also use treats instead of regular food.
  • Brush all the cats with the same comb. Do you brush your cats? Even if you don’t right now, it’s a great idea to start. Cats have scent glands all over their body and if you occasionally brush all the cats, focusing mainly on their forehead, cheeks and chin, you will not only make new cat introductions smoother, but your existing cats will start to bond more.
    woman combing British cat on white background
  • Rub a cloth against the new cat’s cheeks and give it to your existing cat for examination, as it will be full of friendly scents of your new cat. After some time, you can do the reverse by letting your cat examine the cloth containing the scents of existing cat(s). If, however, one of the cats reacts aggressively towards the cloth, this should be postponed.
  • Use the same toys for playing. You can either have the same interactive toy, or you can just switch solo play toys. Again, playing is fun and you should encourage your cats to smell the other ones during fun times.
  • Exchange territories for a short time when you new cat feels completely comfortable in his single room. There are two parts to this: you can lock up your existing cat and let your new cat explore the adjacent rooms, or you can also take the new cat to a different room and let the existing cat explore the place. You can also use toys or foot to encourage cats to explore, but don’t be pushy about it.

6. Introduce the cats by sight

As time passes and the curiosity and confidence of all the cats increase, you can begin with a short supervised face-to-face introduction.

First, tire out all the cats by playing with them. It would best if you could get another person’s help and you can play with all the cats at the same time. You don’t need to tire out all the cats till they are exhausted, but 15 minutes of exercise prior to the introduction will reduce their agitation and hopefully any aggression.

Once you have fed the cats on the opposite sides of the door, you can place your new cat’s dish inside the room as far from the door as possible. And then, while both cats are eating, slowly open the door and crouch down, remaining between your cats in a position where you can shut the door within a second if the necessity arises.

What happens next may differ from case to case:

  • The cats continue eating and pay little or no attention to each other. This is good. Let them finish and slowly close the door. The next time, you may move the bowls closer and/or keep the door open longer and examine what happens next.
  • The cats stop eating but keep their distance. This again is good. Let them observe each other for some time. If you notice any growling or hissing, slowly close the door and leave it open for a shorter time the next time. It is likely that you may have to wait for some days before trying again.
  • The cats act aggressively towards each other. Close the door, and go away. Don’t pay any attention to what happend; do not try to calm or punish the cats. It’s best to leave the situation as is, since it is obvious that the interaction occurred too soon. Get back to scent exchanges and try again, no sooner than after several days.

The above example is just one way of doing the introduction. You can play with the distance of the food dishes and visibility of both cats, and you can also experiment with the food by using something more delicious than regular food. Also, you can use toys instead of food or distract them in other positive ways.

7. Gradually proceed with face-to-face cat introductions

From now on, there are different ways to go about the introduction and there is no one “correct” way. It’s likely that when you first opened the door was actually the last time it was closed. It’s likely to be hard and very gradual process, too.

It’s always best to end any interactions BEFORE any aggression is expressed. Watch your cats’ body language carefully to see when they start to dislike the process and try to separate both cats BEFORE it happens.

If you think the short sessions are proceeding too slowly, don’t try to make them last longer, but have more of them every day. Even when you are able to keep the doors open for most of the day, consider closing them at night or times when you are not home.

Two cats - best buddies

Eventually, you should arrive at a point where you no longer need to close the door, when you no longer need to supervise interactions between your cats and when you no longer refer to your cats as “the new cat“ and “the old cat.” They are all “My Cats!””to you.


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