I just had my 7-month-old male Great Pyrenees weighed at the vet,and he is only 58 lbs. He is healthy in every way and has free access to food. The vet says that he will probably not reach 100 lbs. That's fine with me,as long as he's healthy,but I was surprised because both of his parents are large dogs and that's what I was expecting. Is there any reason to be concerned?