Prepare separate spaces
Give the newcomer a secure room with its own resources. Protect the resident cat’s established routine. A closed door allows both cats to settle before direct contact is possible.
Exchange information through scent
Swap bedding or allow exploration of separate spaces at different times. Pair calm behavior with pleasant experiences. Progress according to the cats’ responses rather than a fixed deadline.
Use controlled visual contact
When both cats appear comfortable, allow short visual sessions through a secure barrier. Keep distance and an easy retreat. If tension rises, reduce intensity and return to an earlier step.
Distribute resources
Provide separate feeding, resting, scratching and litter opportunities. Friendship is not the only successful outcome; comfortable coexistence can also be a good result. Seek qualified help for persistent aggression or distress.
A useful next step
Choose one manageable improvement and make a note of what changes. Use the practical tools to organize the details, and return to the discussion to share what you learned.