[SamiNFurbabies]

I think that it depends on you and your dog---are you willing to change the way you live to accomodate a tiny? Being careful when you shut doors? Even closet doors? Making sure that you don't lock them up somewhere? being careful where you sit? I often find dogs behind the pillows of my couch... or under the quilts.... or right under my feet unnoticed...but I'm always prepared that they will be there---so i make my movements accordingly.
As for your already existing 10lb dog---how is he with tinies or other dogs?
Molly---my 12lber is the most gentle dog ever and she is often bullied by the little ones. She puts up with a lot. If she weren't that way...I would not have brought home a 4 and 5 lber.
She does have a good time with the small ones--she plays with them very gently...she doesn't really use her paws to play with them because she is afraid to hurt them...so she plays tug of war and lets them win lol. She chases them or gets chased...she trips them....it's funny and she likes them.