Bringing home a new cat is exciting, but if you already have a resident cat, careful introductions are key to creating a peaceful household. Cats are territorial by nature, and rushing the process can lead to long-term tension. Here’s a step-by-step guide on how to introduce cats safely and successfully.
Step 1: Set the scene
Help your new cat settle in by giving them their own small, quiet room with a litter box, food, water, toys, and a cozy hiding place (a carrier with a towel works perfectly). Choose a room that doesn’t disrupt your resident cat’s routine. Allow the new cat to adjust there for three to four days before any face-to-face meetings.
During this time, do not let the cats interact directly. It’s normal if they sniff under the door, and this helps them get used to each other’s scent. You can also swap bedding or toys between the cats so each one can start associating the other’s scent with comfort and familiarity.
Spend time with each cat individually on either side of the door (petting, playing, and relaxing). This lets both cats sense each other’s presence in a calm environment, helping to reduce stress.
Step 2: Watch for signs of stress
Introducing cats takes time, and stress is normal. However, if either cat shows intense hissing, growling, or exhibits signs such as not eating, avoiding the litter box, or overgrooming, pause the process.
- If your resident cat seems stressed, contact your veterinarian.
- If your new cat is struggling, reach out to the SF SPCA for advice.
You may need to extend the separation period for a week or more before trying again. Once both cats seem relaxed—no intense hissing or aggression—you can move to the next stage.
Step 3: Supervised interactions
If the sniff visits are going well, it’s time to start supervised interactions. When the cats appear calm, open the door and let the new cat come out and explore. Let the cat come out of the room at their own pace. Forcing the cat to come into a new territory will just make the cat increasingly tense and prolong their insecurity. Let the cats enter each other’s territory for about a half hour. Then separate the cats and repeat this process a few times each day.
If a cat seems overly stressed about the other cat, you can distract the cat with toys or food treats, but be sure to keep the toys four or more feet apart when playing. Sometimes cats play so hard that they forget to be upset about the other cat and start to become accustomed to the other cat’s presence. There may be rivalry for toys, so this may not always work. Treats may also help alleviate this situation, so be sure to give them treats in the presence of the other cats. This will not only distract them, but it will also serve as a reward for not hissing.
At the end of the play or treat session immediately separate the cats. This time apart allows them to be able to process the information they gained while they were together. It also allows them both to regain their sense of territory and confidence, which encourages a favorable interaction at their next meeting. Continue this process daily, lengthening the amount of time they are together a little each session.
Step 4: Handle aggression calmly
Never punish a cat for aggressive behavior toward another cat. Most owners do this thinking they will teach the cat that the aggressive behavior is inappropriate, but it only ends up making the cat more stressed and upset, prolonging the cat-to-cat aggression. The best way to react is either to stay silent, and calmly separate the cats, or to speak softly to the cats.
Step 5: Extra steps for a shy cat
If your new cat is shy, you’ll need to slow things down even more. Allow extra time for them to get comfortable in their safe room and feel secure before meeting the resident cat.
Repeat the introduction and separation steps as many times as necessary, focusing on positive one-on-one time with each cat to build trust. When you’re ready, open the door and let them approach each other naturally without forcing interaction.
Start with short sessions (10–15 minutes) and separate them afterward. Continue this several times a day until both cats are relaxed, not chasing or fixating on each other. Only leave them unsupervised once you’re confident they’re comfortable together.
Step 6: Be Patient
When learning how to introduce cats, patience is your best tool. Some introductions go smoothly within days, while others take weeks or even months. Go at each cat’s pace and remember: you’re building the foundation for a long-term relationship. Moving too quickly can cause setbacks that are difficult to undo.
Most cats eventually learn to coexist peacefully, and many even become close companions. With time, care, and understanding, your multi-cat household can thrive.
Enjoy your kitties—and remember, slow introductions lead to lasting harmony!
Need extra help? If you’re unsure how to introduce cats or you’re experiencing ongoing issues, reach out to our Behavior team for personalized guidance.