Introduction protocols for new cats

I am looking for a consensus on the standard protocol for introducing a new cat to a resident cat in a shared home. I have read several articles, but they often contradict each other on the timing of visual contact.

Currently, I have Olive, a 6-year-old gray shorthair, and Biscuit, a 2-year-old orange tabby. I am considering fostering a new cat soon and want to ensure I follow a structured approach to minimize conflict. What are the essential steps most of you agree on?

Keep them separated by a door for at least a week. My Sam is anxious, so I start with just scent swapping. See scent swapping methods that work for details on how I do it. If they are hissing through the door, you are moving too fast.

The main variable is the temperament of the resident cat. If the resident is shy, the timeline extends significantly. I had to go through this with Bean, a 5-year-old DSH who is quite timid. Check out dealing with a shy resident cat which I started when I was trying to figure out how to handle his fear without forcing interaction.

Feeding on opposite sides of a closed door is a reliable way to build positive associations. I do this for Luna and my new cat Milo. It helps them associate the smell of the other cat with food rather than threat. You can read more about the setup in feeding on opposite sides of the door.

Thank you for the specific references. I will review the scent swapping and feeding techniques. Does anyone have data on how long the visual barrier stage should last? I am concerned about the transition to full access.

It depends on how they react to seeing each other. Watch for stress signals like flattened ears or hiding. If they are calm, you can open the door a crack. If they are stressed, go back to scent swapping. See stress signals to watch for to identify the early warning signs.