How to Introduce Two Cats
By: Beth Hanson
Tags: Cats

Cats are territorial. And they thrive on routine. But introducing a second cat to a one-cat home changes the routine.

That’s why it’s important to choose the right cat. For us, that meant looking for an easygoing kitten (Kingsley) to introduce to our independent older cat (Arya).

And that meant a gradual introduction process — and a whole lot of patience.

How to Introduce a Kitten to An Older Cat

Best practices suggest that introducing a kitten to an older cat is easier than introducing two adult cats. Kittens are less intimidating than adult cats. And, it gives the resident cat the ability to assert dominance.

We also read many, many articles suggesting it was best to take the introduction slowly. There was no set timeline. Most said it could take anywhere from a couple of weeks to a couple of months.

We braced ourselves for the latter. And, it did take a couple of months.

Here are the steps we took and the timeline we followed for introducing Kingsley to Arya.

1. Prepare a Room for the New Cat

It’s ideal to prepare a room before you bring a cat home. But we adopted Kingsley semi-impulsively. So, we prepared a room for him after we brought him home. Oops.

And, we prepared the bedroom on the first day. On the second day, we decided to repurpose our big walk-in closet (with two entrances) as the kitten’s room.

Here’s how to prepare a room for a new cat.

Make sure that the room has:

Food

Water

Litter box

Toys

And, make sure there isn’t anything in the room that the new cat could get into — like charging cords and plants.

Time: <1 hour

2. Wait

After getting the new cat home and comfy in his or her room, the waiting begins. You shouldn’t try introducing the new cat to the resident cat until you’ve gone to the vet.

That’s because the new cat needs to be given a clean bill of health, so you don’t risk the resident cat getting sick.

In our case, this waiting period was extra crucial. While I was playing with Kingsley — a few hours after we adopted him — I got a call from the shelter. Other kittens who came on the same transport as Kingsley had been diagnosed with panleukopenia.

Panleukopenia is a serious, even life-threatening, condition. So, it was a nerve-wracking two weeks while we waited for Kingsley’s vet visit (and looked for signs of the disease).

Time: 1–2 weeks

3. Go to the Vet

Going to the vet is important, especially when introducing cats.

At the vet visit, your new cat gets:

Any remaining vaccinations.

Tested for diseases like FIV and FLV (or, in our case, panleukopenia).

Dewormed.

Examined.

Going to the vet can be stressful for cats. But, for Kingsley, it was no problem. He purred and impressed the vet tech with his easygoing personality.

Time: 1 hour

4. Introduce the Cats — Under the Door

Once your new cat gets a clean bill of health, you can begin the introduction process.

The first phase should be introducing the cats under the door. This gives them the opportunity to sniff each other and see each other — while in their respective rooms.

Arya was very curious about sniffing Kingsley under the door. And she only hissed at him the first couple of days.

It’s also a good idea to have them each eating by their side of the door, so they associate each other with good things.

For us, this phase also involved Kingsley sticking his paws under the door in an attempt to play with Arya. We even encouraged this by getting an under-the-door toy.

Time: 1–2 weeks

5. Introduce the Cats — In a Safe Space

After the cats get used to each other under the door, the next step is to let them see more of each other. But still keeping them partitioned from each other. This can be done through a baby gate.

We took a slightly different route, using the resources we already had.

An upside-down laundry basket. And sometimes the pet carrier.

There was more hissing and growling in this phase. And batting. All from Arya.

Kingsley just sat there, wondering why he couldn’t be out of the cage playing with that other cat.

We rewarded bouts without hissing/growling/batting with treats. And eventually, Arya got used to Kingsley being out.

Time: 2–3 weeks

6. Supervise Their Interactions

The next step is to remove the barrier and supervise the interactions between the two cats.

After we removed the barrier, Kingsley bounded up to Arya right away. And she did not like that.

In this phase, there was more hissing, growling, and batting. And chasing and fighting.

Good behavior during interactions should be rewarded with treats.

Bad behavior should lead to separation — and going back to the barrier for a while.

Eventually, the hissing, growling, batting, chasing, and fighting tapered off. Kingsley learned not to bound up to Arya with unbridled enthusiasm. And Arya learned to chill out and not immediately bat Kingsley

Time: 1 month

7. Leave Them Alone Together

The last step is to leave the cats alone together.

We were nervous about leaving them alone together for too long. The first time we left them alone was for a few hours while we went out to a brewery.

When we got back, they were both still alive and unharmed. So, we tried a full day. And before long, we were able to leave them alone together every day.

Time: 1–2 hours, to start

So, How Long Does It Take for Cats to Get Used to Each Other?

It depends. Some cats will adapt quicker than others.

It took Kingsley and Arya about two months to get used to each other. That meant that, two months after adopting Kingsley, we could finally leave them both alone together in the apartment.

Time: 2 months

How to Get Two Cats to Like Each Other

It takes longer for cats to like each other. Again, some will like each other more quickly than others.

For us, it took another two months — four months after we adopted Kingsley — for both cats to like each other.

For Kingsley and Arya, liking each other meant taking naps together.

Liking each other also meant teaching each other things.

Arya taught Kingsley how to beg for food. “When the humans walk down the hallway, run past them and cut them off at the cupboard where the cat food is stored. Look up, meow, rub against the human’s leg, and then look at the cupboard. They’ll eventually get the message.”

Kingsley taught Arya how to get attention. “When you want the female human’s attention, bat her necklaces.”

Liking each other also means working together. Arya and Kingsley work together to get food — or to try to sneak out of the apartment.

Lately, liking each other also means hanging out in open windows.

Time: 4 months

Introducing Two Cats Takes Time

Introducing two cats takes time, but in the end, it is so worth the effort.

Considering whether you should get a second cat? Here’s how to tell if your cat needs a companion.