Opposite experience for me, we went from 1 to 3 cats by adding the new cat every 6ish years.
Didn't really do anything special, just brought the new cat home and that's it. Maybe has to do with all of them being from the same breed (Oriental shorthair) and the specifics of the breed itself
I wouldn't lose it immediately, because I didn't drop Black Clover in the first 10 episodes and it was one of my favorite shows for the next 160