Introducing a new cat or kitten into a household with cats

Welcome back to the series “Introducing a New Pet to your Tribe.” You can read Part 1: Dogs here.

In this part of the series, I’m going to give you some tips on introducing a new cat or kitten to the household.

This is a stressful time for all the felines involved. An inept or badly done introduction can set up a situation where the cats never do get along. Sometimes things are so bad that one of the cats needs to be rehomed.

Let’s avoid that, ok? There are a lot of things you can do to prevent this outcome!

It is much harder to get an adult cat that has never lived with another cat to accept a new cat into the tribe. Your cat’s prior experiences with other cats will have a big influence on whether they will accept a new cat or not. Even if your cat has never lived with another cat before, you can have a successful outcome if you take things slowly.

While we tend to think of cats as being solitary creatures, in truth domestic cats are social.

Feral cats will often live in social groups, called colonies. These are usually groups of related females and their offspring but sometimes include non-related members. Unlike dogs, however, cats do not develop a social hierarchy. There is no “leader” in a cat colony.

This makes it a bit trickier to introduce a new cat to the household. Our dogs naturally (reinforced by training) look to us as the leaders of the pack. This is very helpful when we are bringing in new members to the family.

Cats, on the other hand, tend to resent another cat’s intrusion into their territory. They do not specifically look to the humans in the house as leaders (I wish!). This means we can’t use our position in the hierarchy to smooth things over for them.

Cats also do not like change and adapt slowly to changes. While a new dog will usually settle in a a few weeks, it can take cats a month or months to settle in and adjust to a major change.

I strongly recommend using a product like Feliway for cat introductions. If you have a large house, you may need several diffusers to cover the areas that the cats spend the most time in. Feliway has pheromone collars, if that works better for your situation. There is a specific Feliway diffuser for multi-cat households. You can find a link to it here.

You could also use Zylkene on all the cats in the household during this introduction period.

The first day or so: Phase 1

On the day you bring your new cat home, you will want to set them up in an isolated area of your house. I recommend a bathroom, as that is an easy area to keep clean if there are any accidents. Also, using a bathroom will prevent the new cat from hiding in places you can’t get to. You can certainly use a bedroom, but try and prevent them from having access to closets or under the bed.

Your new cat will spend the first few days in this room, with the door closed.

Set the room up with a fresh litter box, water, food and a box or crate for them to hide in. Feel free to spend as much time in the room with the new cat as you can. If they are scared or hiding, let them. Don’t force affection on them but certainly pet them if they are receptive. Make sure they are eating and eliminating properly.

It probably won’t take your cat long to discover that something is going on in the bathroom.

Most likely they will be sniffing outside the door. They may look upset.

It is typical for their fur to stand up, for them to be pacing stiffly in front of the door and/or arching their back. They may meow and/or growl. Your cat might start attacking the door or slip their paws under the door.

Let them do this. Obviously don’t let them be destructive, but all that pacing and sniffing is good. This is going to take some time. Try to keep the door between the cats. It does not help much at this phase to let the cats see each other. They both know another cat is in the other side of the door.

If the new cat is a kitten, they will probably adjust quickly.

Kittens are usually not as territorial as adult cats and deal with change faster as well. If the new one is an adult cat it may take a bit longer before they feel safe enough to enjoy being petted and are ready to explore their surroundings.

Keep the new cat strictly isolated for about 24 hours. By then you should have an idea of how they are settling in and how your other cat or cats are adjusting to the change.

Once the new cat is able to relax and explore the room and doesn’t seem worried (or even better is excited and happy) when you come into the room, you can move on to the next phase. 1 to 3 days seems to be the average for this first period. Let the cats behavior be your guide. If either the new or existing member of the cat family still seems really stressed, give it another day or so before you move on.

Meeting face-to-face: Phase 2

The next step is to let the cats see each other and have some limited interactions.

For this phase, I use a baby gate so that the cats can see and smell each other, but can’t scratch or bite. The way I do it is to set up the gate at the bathroom door, open the door a bit and then I sit in the bathroom in front of the gate. This way I can intervene if there is a problem, or close the door quickly if I need to.

If you don’t have a baby gate and can’t buy or borrow one, you can also use a piece of cardboard with some small holes cut in it.

You want them to be able to see each other but also have them see there is something separating them.

The first time I do this, I usually only leave the door open for a few minutes. It really depends on their reactions. If either cat get really upset I stop and let them have a few hours of relaxation before trying again.

Do this several times, each time leaving the door open a bit longer. It is common for cats to hiss at each other during this phase. Hopefully each time you do this, the cats will react less negatively to each other.

For me, Phase 2 usually lasts about 24 hours, with at least 5 baby-gated introductions.

Take as long as is needed. You are waiting until the cats are relaxed enough when they see each other that they do not try to strike out or fight. It’s fine if they are still hissing and even growling a bit. If either cat is arching its back or trying to fight then take more time and repeat this phase.

Remove the baby gate: Phase 3

The next step is to let the cats meet up without the baby gate or barrier in the way. Keep it handy the first few times, though, in case you need it. As in phase 2, I usually sit in the bathroom doorway between the cats and let them meet. If they are receptive, I will pet them both at the same time.

Depending on how this introduction goes, I may let the new cat start exploring the rest of the house at this point.

If either cat still seems very upset, or if they are lashing out at each other I will take more time. Do this moderated introduction as many times as needed until things are working.

Leave the litter box and food and water dishes in the bathroom for now, even if the new cat is exploring the house.

Gradually move the litter box and food dishes to the place you want them to be.

If you free feed your cats, you will need to keep an eye on things and make sure all the cats are getting a chance to eat. Most of the time, a stressed cat will not eat, so it may take a while before the cats will share a bowl of food. Cats do not always like to share a litter box either.

The rule of thumb for litter boxes is to have 1 litter box per cat, plus one.

So, for a three cat household you should ideally have 4 litter boxes! This doesn’t work for everyone, but I do recommend a minimum of two litter boxes in a multi-cat household, preferably located in different places. Obviously you want to keep the litter boxes clean and scoop them frequently.

Especially in the first few weeks, you want all the cats to feel safe when they are using the litter box. Otherwise they might not use it as they should. Having the litter boxes in different areas make it more likely that one cat will not intimidate or bully the other when they are trying to go to the bathroom.

Adding a new cat to an existing cat household can be tricky. I hope that by using this gradual, phased introduction you will get things off to a positive start!