Keep the new cat in a separate room at first
Provide separate food, water, litter boxes, and resting areas
Let both cats get used to each other’s scent by swapping bedding
Feed them on opposite sides of the closed door
Allow short visual introductions through a baby gate or cracked door
Watch for calm behavior before increasing contact time
Use treats and praise to reward relaxed behavior
Keep initial meetings brief and supervised
Separate them if hissing, growling, or chasing starts
Increase shared time gradually as they stay calm
Maintain multiple litter boxes and resources in different areas
Give each cat individual attention
Move at the slower cat’s pace
Consult a veterinarian or behaviorist if aggression continues