
Hi,
I dont own dobes either, but puppys are usually NOT the best judge of how much exercise they need. I would definately not let a large breed pup (or any breed pup for that matter) charge about to their hearts content. They can and will over knacker themselves, which, whilst great for getting them to go to sleep, is really bad for their bone growth.
How much are you training your pup. Brain exercise is as important, if not more so, for a puppy, and will actually knacker them out just like physical exercise.
It is never too young to start training, just keep it fun and fair. Always end on a good note, rather than getting frustrated and giving up. Clicker training is brilliant, especially for pups. It took me only 5 minutes to get my 7 week old pup to learn to sit, and come, instead of mugging me for food, then ignoring me when i want him.
Pups, in fact all animals, even us, learn far more easily and more quickly and more effectively when they are young!
Emma