How to introduce a new cat to an old cat

Bringing a new cat into a cage
After bringing home, immediately put the new cat into the cage so that there is no fight with your old pet cat. Leave the new cat in a cage for a few days (the longest a week) to explore its new home safely. Make sure to bring your old cat close to a cage that contains a new cat. The goal is for both cats to get used to each other and the body smells of the two cats can be accepted by each other.

Take the new cat out of the cage.
If within a few days the old cat does not show dislike to the new cat, immediately remove the new cat from its cage. Next, leave the new cat with the old pet cat to get closer to both. But keep an eye on both.

Have fun for both cats.
When the situation is favorable, give entertainment to the new cat and the old cat to further strengthen their relationship. You can bring them to play together or feed each other. If there is no major fight, the two indirectly have begun to work out and can live together at home. However, you still have to keep an eye on both of them to make sure there is no struggle.