Rushing this is the most common mistake. Cats build tolerance through scent and gradual exposure, not face-to-face meetings on day one.
What you'll need
A separate room for the new cat, two feeding stations, and roughly two weeks you're willing to be patient about.
Steps
- Keep them fully separated at first
New cat gets their own room with everything they need. No visual contact yet, just proximity through a closed door.
- Swap scents before swapping space
Trade bedding or a soft cloth rubbed on each cat between rooms daily. This lets them get used to each other's smell without any pressure.
- Feed on either side of the closed door
Pairing food with the other cat's presence builds a positive association over time, gradually moving the bowls closer to the door as days pass.
- Allow supervised visual contact
A cracked door or baby gate lets them see each other without full access. Keep sessions short and calm, ending before any tension builds.
- Progress to short shared time in a neutral room
Not either cat's main territory. Keep initial sessions to a few minutes, with treats and calm distraction on hand.
- Extend shared time gradually over one to two weeks
Watch body language throughout, flattened ears or a low growl means you moved too fast. Going back a step is normal and not a failure.
Frequently asked questions
How do I know if it's just adjustment hissing or a real problem?
Occasional hissing during the early stages is common and usually resolves. Ongoing stalking, cornering, or refusal to eat are signs to slow down significantly.
Does age difference make this harder?
Often, yes. A older, settled cat and a young kitten typically adjust faster than two adult cats with established territory habits.