My Yorkie is 4 years old and came from a breeder. She was released to a no killer rescue organization which is who we adopted her from. We are the first family she has ever had. Everything is new to her, we had to start from scratch like she was a new born pup. She only knew the kennel and having pups. They say that when you adopt an older dog there is a "honeymoon" period of 4 to 5 weeks then they start to act like themselves. We have not had any issues with her (other than separation anxiety), we have had her about 6 weeks now. She is a sweet little girl who loves being with us and having lots of attention and special treatment. We were not allowed to have her vet checked before we adopted her which concerned me. But we took a chance on her and so far so good!