My 6 month rotti is only 53lbs and should be around 77lbs!! He eats 6 cups of food a day (neutro large breed puppy)! What can I do to increase his weight? His parents were huge! He was the pick of the litter as well. I know it is not a worm problem, I keep him on his meds and he was recently checked. What can I do? His father weighed in at 3 yrs of age nearly 200lbs, and his mother at 3 is almost 160. Will he ever catch up?