My Yorkie was 5 pounds at 18 months, he is now 2 yr 9 mths old, and has gained a pound to 6 pounds. I wouldnt worry, except for his belly is really budgy and round! And larger than his chest by far, and I don't see his ribs at all. I wonder if I am feeding him too much (1/4 cup dog food and chicken mix w/ lots of veg's) twice a day. With the extra vegetables it will be a lot more than 1/4 cup. Any suggestions?? I don't want this little guy to be unhealthy!