A little while ago I sadly lost one of my senior girls to old age, and last week I brought home a new rescued youngster. I've been unusually lucky in the past that my cat pairings have taken to each other almost immediately, but these 2 have not. So I'm now in the process of acclimatising my resident cat (13 but very fit and healthy) and a new rescue (age unknown but young adult). They've both lived happily with other cats before but understandably are unhappy about each others presence at the moment. New girl has a safe room with everything she needs and existing cats has my bedroom to herself, which has her catflap in. We live in a ground floor flat in a safe rural location and senior girl by choice spends a good bit of Time in the garden. That's what she likes.
As of today they can be in each others presence for a short period as long as I keep new girl busy and distracted with toys and treats. On noticing each other they will make some unhappy noises and new girl will start making fear aggressive motion towards resident, particularly if resident moves around, so I distract again and she goes back in her room. I'm aware this isn't bad, for cats that have only just met; I've certainly heard worse. I've just been unusually lucky with previous pairings. So my questions: how long would you keep them at this stage of short exposures? A few days? A week? Then what should the next stage be? How often would you expose them? Once a day, or twice a day? More? I am scent swapping by brushing them with the same brush. Newbie needs to lose her fear aggression towards resident before we move forwards. I'm off work in July so I have time to get this right.