It's funny you ask this - because it is precisely due to rehoming an adult dog that we came to have our Yorkies. I've told this story before - so if you've read it, sorry!
We had a Jack Russell terrier - my husband had always wanted one and our Jack was adorable, smart, and FULL of ENERGY. When my husband got sick with heart failure and was in and out of the hospital every other month or so for a year - Jack just didn't have the exercise and attention that he needed and he was just wild. He would tear up things in the house when my husband was gone - the leather couch
and other things. We just could not control him, because we could not give him the exercise and attention that he needed when my husband was sooo sick.
We tried to find him a home with people we knew, but were unable to. We contacted the JRT rescue group and we ended up giving him to the Navy. The Navy uses JRTs for drug detection dogs on the ships. The dogs live with the handlers and are retired after a five - seven year career - where they either stay with the handler or are placed with other naval families, if staying with the handler is not possible.
Was it a hard decision - you bet! Did we cry - you bet! Was it the best for our Jack - you bet! Jack always had to have something to do - that was the problem after my husband got sick. I know that Jack is so happy doing his job now.
Anyway, there is a happy end to this story. One day a few months after Jack left us - we saw some JRT puppies. My husband started to cry, big ole tears just streamed down his face. That is when I knew that we had to get a dog that would fit our quiet lifestyle - now that my husband was disabled.
We did lots of research and we decided on a Yorkie. Thus, Rowdy came into our life and as my husband says, "He is the light of our life". A year later we added Rexy and we are so happy to have them with us.
Anyway, the point of the story is that, even though it was a painful decision, it turned out best for everyone. We look back now with very fond memories of Jack - but we are happy that he is where he is active, busy and can be doing things he loves every day. We are thrilled with our Rowdy and Rexy and couldn't be happier now - even though it was very painful at the time. When someone, who doesn't know him, asks my husband about his occupation - he says that his job is "holding dogs"
Rex and Rowdy live to sit in his lap and he lives to be there for them. It is a mutual admiration society!
Good luck with your decision.