
Calgary Humane Society
If you have been thinking about adding a feline to your life then now is a great time to do it! Check out these tips on how to introduce a new cat to an existing resident cat in the household.
No sudden introductions please!
Cats are creatures of habit, meaning they don’t like change. Cats thrive on ritual and love to know that today will look the same as yesterday while tomorrow will look the same as today. If you have ever noticed that your cat seems to know your routine better than you do, now you know why!
So what does this mean for bringing home a new feline friend? Well adding a new feline to the home is a HUGE disruption for a resident cat. While we humans may not notice, a new cat brings brand new smells and sounds to a home where the resident cat already has a firmly established territory. So does that mean these two cats can never be friends? Not at all, but gradual introductions are key to feline friendships.

Step 1: Establish a safe space for the newbie
Before bringing your adopted cat home, set up a room (preferably a room that is away from the resident’s cat most favorite space) that contains everything your new feline will need. That means a litter box, food, water, bed, toys, scratching post etc. This room will be the primary residence for your new feline for the next little while, so comfort is key! While you are building this home within a home, include extra towels and bedding and also put extra towels and bedding out for your resident cat – you will need them for scent swapping!
For the first few days, the new cat will stay in this room, so make sure to go and visit with your new kitty frequently to enhance your developing bond. Always remember though, resident cats need attention too! Make sure to spend equal amounts of time with each cat. Spending time with each cat not only helps reassure the resident cat that they are not being usurped, it also helps mix the new cat’s scent into the home and gives that scent a positive association (you come into the room smelling like the new cat and give the existing cat lots of positive attention and praise).
Step 2: Scent swapping
After your new kitty has had an opportunity to settle in for a day or two you can start swapping scents. You may have noticed that both cats have already shown an interest in sniffing at the crack under the door, and that’s great, but it’s time to up the ante! Take a towel or piece of bedding that has the resident cat’s scent on it and place it into the new cat’s room. At the same time, move a piece of the new cat’s bedding out into the resident cat’s space. When you add these scent items, make it a positive experience with plenty of treats, play and pets. The idea is you want the scent of the other cat to be associated with happy things. Never force your cat to smell the new scent item or push them to stay in close proximity to it.
To put this in a more human perspective – have you ever done a team-building event at a workplace or volunteer organization? If you have, you have experienced something similar to what you are trying to set up for your cats. Team building experiences are designed to deliberately bring people together into non-threatening interactions doing fun activities. This builds an association between the people you work with and the idea of “fun” and “teamwork”. So think of scent swapping as team building for cats.
If your cat hisses, spits or avoids the new scent item, you will want to place it away from places that are important to your cat (litter box, bed, food bowl, water dish etc). Some cats are less social and take longer to get used to the new scent than others. As your cat becomes more comfortable with the scent item, gradually move it closer to the cat’s food bowl, as you ultimately want the scent of the new cat to be paired with the positive experience of food. If you find this exercise taking several days or longer you may need to replace the scent items a few times.
Scent swapping is complete when the cats are completely comfortable with the scent of the other cat – meaning you can rub the cheeks of one cat with the towel that has the scent of the other cat. Cheek rubbing is not only a sign of territory marking, but a sign of friendliness in cats, and the scent of their cheek glands is a way to pass this important information on, so cheek rubbing is definitely an important part of this process!
Step 3: Field trip time
Once your kitties are comfortable with each other’s scent, you can swap the rooms they live in back and forth. Place the resident cat into the new cat’s room and give the new cat run of the house for set periods of time. This helps integrate the smell of each cat into all of the living space.
Step 4: Visual contact
This step will greatly depend on what you have available for your household set-up. If you have the ability to use a screen door to separate the two rooms then that is ideal. Unfortunately, 99.9% of homes do not have screen doors and solid doors on every room. If you don’t have a screen door, you can use a baby gate (but you will need to block all access over top of the baby gate to prevent the cats from jumping over) or you can open the door a small crack, using door stops on both sides to hold it in place. The idea is to have a crack large enough that the cats can see each other but not large enough that either cat could get in or out of their space. When you crack the door or set up the gate, put food dishes filled with tasty wet food about 4-5 feet from each side of the gate/door. If both cats eat the food, you can move both dishes a little closer to the door/gate. If either cat refuses to eat, then move the dishes backwards. Keep doing this until the cats can comfortably eat beside the door or gate together. Remember: you are looking for a positive interaction EVERY time, so don’t rush it! You want to establish the idea that the “new cat” brings all kinds of awesome things with them when they show up.
Once the cats will comfortably eat near the door, you can try a proper introduction by having the door open enough that the cats can freely enter or leave through the door. If there is growling, hissing or spitting at this stage, back up and go back to feeding for a few days. At first you will want to restrict this free-roaming interaction to times that you are home to supervise, gradually working up to leaving the cats together full time. Some cats are more social while others are more aloof. The end goal is to have two cats who will live together peacefully, so don’t worry too much if your cats decide to mostly ignore each other. Much like human roommates, feline roommates will develop their own ‘rules’ around how much time to spend together and who is allowed to control the TV remote (or, in the case of cats, sleep in the favorite bed/occupy the favorite window).
Step 5: Keeping the peace
Like all living things, cats who live together may occasionally annoy each other. Hearing the occasional hiss or grumpy growl is pretty normal in a multi-cat household. What you should watch out for though are signs of consistent bullying or fighting and signs of severe fighting. If one cat is constantly kept on the run by the other cat or denied access to things that they need (litter box, food etc.) those are signs of bullying. If you notice this, go back to scent swapping and begin the introduction process again. If that doesn’t work, we suggest calling our free behaviour helpline here at the shelter to talk to one of our behaviour counselors.
Likewise, if you notice hissing is escalating into violent fights (resulting in blood loss, fur flying or other injuries to the cats or humans in the home) then you will need to take immediate action. Immediately separate the cats into their own living spaces (like step 1 of the introduction process) and call our behaviour helpline to get more guidance.
Taking a look at your living space will do a lot to enhance peace in a multi-cat home. Look for areas where one cat could ‘trap’ the other cat (areas where there is only one entry/exit point – like doorways). Try to avoid setting up important things (like litter boxes) in areas where a cat could get ‘trapped’ by another cat. Ensure that favorite places (beds, windowsills etc.) have at least 2 access points so both cats can make an escape in different directions if an argument erupts.
Finally, peace is MUCH easier to keep if everyone has what they need. Many cats are not big fans of sharing, so having enough of the “important things” will really help reduce arguments. In terms of litter boxes, you should have one for each cat plus one extra (so for 3 cats you should have 4 litter boxes). Each cat should also have their own food and water dish. Having a selection of toys available is always a good idea but if you notice both cats prefer the same kind of toy think about adding a few duplicates. If you have the space and the money to have multiple cat trees/condos your cats will probably thank you, but if this isn’t a possibility then purchase the largest cat tree your budget and space allow for and just keep an eye out to make sure nobody is hogging all the tree/condo time.
We hope you found this helpful! Have you successfully introduced cats before? We would love to hear about your experience! Share a story about what techniques you found successful and how long it took your cats to get used to each other on our Facebook page!