Hello, We have a 7 month old bench lab "Sam". Sam is our first bench lab and I'm a little concerned with his size. His height (19.5 inches at the withers), and his weight (52 lbs. at 31 weeks) are both within the expected height and weight according to online charts. Our concern lies in his length as he appears to be a bit short. Our Vet says he is healthy and wasn't at all concerned with his size. He is a happy and active pup and plays all day long with our older Lab. He has a voracious appetite and is a joy to have. Should I be concerned? Thank you.