Hi Nicholle! And congratulations on your Rottie pup!! Gee, I'm trying to remember back to when my girl was that age. I remember that we didn't walk too far. In actual distance, maybe to the end of the street and back, about 100 yds. We have a big back yard, so mostly she played and romped around there. The breeder suggested that I not let her run at all for a few months, as it might injure her hips. (She's a Lab) I do know puppies have a lot of energy, but they are growing, and rapidly, and often tire out quickly. I don't think I ever heard my Star whining though while walking. I could usually tell when she was tired, and a few times I did have to carry her home!! Has he been for his first puppy check up yet? If you think he is whining in pain, I might want to give the vet a call. As for being "slow," puppies have a very short attention span, and maybe he is just distracted, exploring the universe!! Hopefully, more experienced puppy Mom's may chime in! Love to your puppy!!