We brought Jo home at 16 weeks and he weighed 2.3. He's now 14 months old and weighs about 3 1/2 pounds...he's bulked up a bit since he got neutered. Riley was brought home at 14 weeks (if I remember right) and he weighed 2.9. He's now almost 9 months old and weighs 4.4 but he's solid muscle...Jo has the equivelant of a Yorkie 'pinch an inch'
Riley was just neutered last week so I imagine he'll probably gain a little now too.