Good Afternoon, I have a 16 week GSP, born January 27th and he appears very undersized. 1: He seems undersized. I took him to the vet today and he weighed 20 pounds, without breakfast, so maybe he is typically 21 or 22. I have looked at charts online and this seems like it is significantly below the average, is this something to be concerned about? Is there a specific puppy food that would better help growth?