After having Angus for 10 yrs with only Keisha, I thought he'd never get used to another dog, that's why I wanted to get a pup. He never seemed to like any dog that already has it's own "personality". But after a couple of days, he was fine. The same goes with Huney (but she DID already have her own personality!), it just took him a couple of days, and then he was fine with her!