New adopters 6 min read Draft · vet review pending

Introducing a new cat to your cat

Cats don't do instant friendships. Rush it and you can get months of hissing. Go slowly, one step at a time, and only move on when both cats are relaxed.

Time: a few days to a few months Rule: the slower cat sets the pace

You'll need

A separate room for the new cat, with its own litter box, food, water, bed and hiding spot
For the whole home: one litter box, food bowl, water bowl and scratching post per cat, plus one extra, in different places
A few soft cloths or blankets, for swapping smells
Favourite treats and a wand toy

Step by step

Vet check first.
Get the new cat checked and tested for common infections before it meets anyone.
Done
New cat in its own room.
Carry it straight there and let it come out of the carrier by itself. Stay at this step until it explores confidently. That can take days.
Done
Swap smells.
Every day, swap a blanket or toy between the cats. Once that's calm for a few days, rub a cloth on one cat's cheeks and leave it where the other can sniff it.
Done
Play on both sides of the door.
Tie two toys together on a string and slide it under the door so each cat plays with one end. Keep it to 5 to 20 minutes.
Done
Swap rooms.
Shut your cat in its favourite room with treats, and let the new cat explore the rest of the home for a while. Then swap back.
Done
Let them see each other.
Short sessions through a glass door, a tall baby gate or a door held slightly open with a strap. Treats and play while they watch.
Done
Short visits in the same room.
Start with a few minutes, with someone helping if you can. Reward calm behaviour. Keep a pillow or cardboard nearby to block a stare-down. Build up over several days.
Done

Hissing isn't failure. It just means "too fast". Go back a step for a few days.

Slow down if you see

Hissing, growling, a flicking tail, or pacing
Staring, or one cat avoiding the swapped smells
Peeing or pooing outside the litter box
Any change from normal behaviour

Never pick a cat up in a tense moment. Put a pillow or toy between them to break eye contact.

The most common reason cats don't get along is not having enough of their own things. Make sure there's always one more of everything than you have cats, spread around the home.

Where this comes from

American Association of Feline Practitioners: step-by-step guide to introducing a new cat (2024 Intercat Tension Guidelines)

This guide is a draft and hasn't been checked by a vet yet. If cats are fighting and hurting each other, talk to your vet.