From my research I've learned that overeating in shelties can be a real problem They'll eat as much as you feed them although I'm sure there are exceptions. My Fergus is one that eats very little and won't eat more if you offer. Then I've got Baxter the chow hound. I know how how ended up weighing almost 60#. That being said I wouldn't worry too much about Trapp right now. As you said he's growing a lot and is very active. I'm sure he's burning up those calories. I'd just keep a close eye on his weight and if you notice he's getting a little pudgy then I'd cut back just slightly on his food.

