Hi, I just brought my GSD puppy home 5 days ago. He's AKC registered. He has his vaccinations and received worm medication. I believe the breeder is trustworthy, based on a friend's recommendation. But I didn't know anything really about GSDs or even dogs and I'm worried there could be something wrong with him. He seems to be far off the average weight for his age. He's also pretty low energy. I thought he'd be bouncing off the walls, but he pretty much lays around at my feet all day. He eats well and is excited to eat. He's ok on walks, but sometimes tires out. I think I overwalked him the first couple days (we would be out for an hour at a time or more 3-4 times a day). He gets pretty energetic around other dogs, but other than that he's pretty mellow even outside. I took him to the vet, they didn't say anything was wrong. He's good tempered and very friendly. I don't care if he grows to be a big dog. And I'm fine, even relieved, if he's a low-energy dog. I just want to make sure he's healthy. Any advice? Has anyone else had a GSD that was this small at this age. I've read other posts of people saying they were worried about their dog's size and all of those dogs were bigger than mine. The breeder gave me Arcana Heritage Meats food to feed him, but it's not puppy food. Am I underfeeding him with this adult food? If the breeder had been feeding him adult food all along would this account for his small size? Thanks in advance for any advice or words of encouragement.