Introducing Your New Cat to a Resident Cat
Congratulations on adopting a new feline family member! Now it is time to prepare for a period of adjustment for both cats in your home. The most important aspect when introducing your new cat to your resident cat is time. Contrary to popular belief, it doesn’t matter if your new cat is the same age, gender, or size as your resident cat, their relationship will depend on each cats’ level of socialization and personality. If your resident cat has never lived with another cat, it may take longer for them to accept a new cat into their home. Taking extra time with the initial introduction will give your cats the best chance at becoming companions.
Step 1: Before bringing your new cat home
Before you bring your new feline friend home, set up their space. Your new cat will need to be completely isolated before you begin introductions to the rest of the home and any resident animals. A spare bedroom or large bathroom is ideal, with access to their own food, water, comfortable resting place, clean litter box, and scratching post. This room will need to have a door that closes completely. If there is a crack under the door, it should be blocked with a towel.
Step 2: Complete isolation from resident pets
Bring your new cat home in a carrier and go straight to their prepared space. Open the carrier and let them come out and explore the room on their own. Leave the carrier in the room so your resident cat does not come upon it. Keep in mind that cats are sensitive animals, and your new cat has likely just been through a lot of change and stress. This period of alone time allows your cat to relax and get to know the sounds, smells, and people in their new home.
There is no set amount of time to keep them isolated. It could be days or weeks, but you must wait until both cats are completely settled and relaxed before you move to the next step. We recommend erring on the side of too much time to avoid causing unnecessary stress by not waiting long enough.
Step 3: The scent exchange
Now you can begin to let the cats get used to each other’s scent. Watch where they rest or sleep and put a T-shirt or towel there for them to lay on. Once their scent is on these items, put the item in the other cat’s area. Do not set it on their sleeping place, simply put it somewhere in the open for the other cat to investigate in their own time. You might be surprised by the reactions you see! Once both cats are completely comfortable with each other’s scent you can move to the next step. Again, err on the side of too much time.
Step 4: Creating a positive association
Now that they are comfortable with each other’s scent, you can begin to create a positive association by removing the towel from the crack in the door and feeding each cat on far opposite sides of the door. Start at a distance where they are comfortably eating and over days (or weeks, depending on the cat) decrease the distance between them. This will help each cat figure out that good things (food) happen when the other cat is nearby.
Step 5: Love at first sight?
Ideally, this step would involve the cats observing each other from a distance, but this is difficult in most home setups. One way to let them safely see each other is to open the door an inch or two using door stops. Another option is to use stacked baby gates to create 5-7 feet of height to prevent your cats from jumping over them (picture on right).
Continue to create a positive association by offering treats or small amounts of canned food while they are in view of one another. The treats or food should be offered at a comfortable distance so that neither cat is hissing or displaying a tense body. If you see these behaviors, slow down and go back to feeding with the door closed. This should be done a few times a day, slowly decreasing the distance between them. This could be done over the course of a few days or weeks. Do not proceed until both cats are comfortable in one another’s presence.
Step 6: Exploring the new environment
Now you can begin to let the new cat out of their isolated space to explore the rest of the home. The resident cat should be confined to a room with the door closed and access to their own food, water and litter box. Do this once or twice day for about an hour until your new cat is relaxed in the new parts of the home.
Step 7: Together at last
Finally, it is time for them to be together! It’s a good idea to add extra resources such as perches, scratching posts, litter boxes, food, and water bowls throughout the house. There should be one person present to interact individually with each cat and monitor their behaviors. This allows the cats to comfortably be in the same room without having to focus on each other. Interacting can include playing with a wand toy, petting, or any activity the cat enjoys. Never leave the cats alone unsupervised. If you do start to see fighting or aggression, such as hissing or growling, be prepared to break it up by tossing a pillow or blanket as a distraction. Bring the new cat back to their isolated space and start again at step two. You may also refer to our “Aggression Between Cats” handout.
If your cats are not getting along and you continue to see aggression, you may need the help of a professional. Call or email the WHS Behavior Line at behavior@wihumane.org or 414-431-6173 for expert advice.
