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How long should I wait to introduce my new cat to my existing cat?

Updated On September 23rd, 2025

Pet's info: Cat | Siamese | Female | spayed | 4 years and 9 months old | 9 lbs

How long should l wait to introduce cats to each other?

4 Answers

Most Helpful Answer

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Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on February 22nd, 2017

I would introduce them slowly to each over the course of about two weeks. I can give you the method I recommend for introducing new cats to each other: Take the new cat, and put her in her own room with her own food, water, and litter box. Keep the door closed, and for a few days, feed them both treats on other side of door so they associate each other's smell with a good experience. Then let the other cat in the new cat's room while the new cat is in a cat carrier. They can smell each other, but not be in contact. If either becomes upset or show signs of aggression, remove the second cat from the room, and try again later. Praise them when they interact appropriately. When they are interacting well with each other through the carrier, you can let the new cat out of her room, and see how she interacts with the other cat. Praise them when they interact appropriately, and separate them with any sign of aggression or upset. I would get a cat tree with lots of shelves to give the cats vertical space to get away from each other. I would keep the new cat in her room when you go out until they are comfortable with each other.

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Related Answers from Veterinarians

  • Image profile

    Answered By Dr. Melanie, BVSc MS

    Veterinarian

    Published on February 20th, 2017

    I can give you a method for transitioning your cats into your mother's home. I would slowly introduce them to each other. Take your cats, and put them in their own room with their own food, water, and litter box. Keep the door closed, and for a few days, feed them all treats on other side of door so they associate each other's smell with a good experience. Then let the other cats in your cats's room while your cats are in cat carriers. They can smell each other, but not be in contact. If anyone becomes upset or show signs of aggression, remove the other cats from the room, and try again later. Praise them when they interact appropriately. When they are interacting well with each other through the carrier, you can let your cats out of their room, and see how they interact with the other cats. Praise them when they interact appropriately, and separate them with any sign of aggression or upset. I would get a cat tree with lots of shelves to give the cats vertical space to get away from each other. I would keep your cats in their room when you go out until they are comfortable with each other.

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    1Pet Parents found this answer helpful

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    Answered By Dr. Melanie, BVSc MS

    Veterinarian

    Published on April 13th, 2017

    Congrats on your new cat! It's common that existing cats will take time to accept a new cat, and I can give you a method to help them get along. I would slowly introduce them to each other. Take the new cat, and put him in his own room with his own food, water, and litter box. Keep the door closed, and for a few days, feed them both treats on other side of door so they associate each other's smell with a good experience. Then let Gizmo in the new cat's room while the new cat is in a cat carrier. They can smell each other, but not be in contact. If either becomes upset or show signs of aggression, remove Gizmo from the room, and try again later. Praise them when they interact appropriately. When they are interacting well with each other through the carrier, you can let the new cat out of his room, and see how he interacts with Gizmo. Praise them when they interact appropriately, and separate them with any sign of aggression or upset. I would get a cat tree with lots of shelves to give the cats vertical space to get away from each other. I would keep the new cat in his room when you go out until they are comfortable with each other.

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    1Pet Parents found this answer helpful

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    Answered By Dr. Melanie, BVSc MS

    Veterinarian

    Published on January 2nd, 2017

    Moving into a new home is very stressful to a young cat, and it's understandable that he's going to be frightened, want to hide, and act antisocial. Add an additional cat into the situation, and that's going to cause him more stress. I would separate the cats, and put the male in his own room to introduce him to the house and the other cat slowly. Make sure he has his own food, water, and litter box. Keep the door closed, and for a few days, feed both cats treats on other side of door so they associate each other's smell with a good experience. Then let the other cat in the kitten's room while the male is in a cat carrier. They can smell each other, but not be in contact. If either becomes upset or show signs of aggression, remove the second cat from the room, and try again later. Praise them when they interact appropriately. When they are interacting well with each other through the carrier, you can let the male out of his room, and see how he interacts with the other cat. Praise them when they interact appropriately, and separate them with any sign of aggression or upset. I would get a cat tree with lots of shelves to give the cats vertical space to get away from each other. I would keep the male in his room when you go out until they are comfortable with each other.

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    1Pet Parents found this answer helpful

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