Training is essential if you want to be able to handle 140 or more pounds of dog and have them listen to you! Start training puppies as soon as you bring them home, even before, if you can. They will lap it up. All they want to do is please you. It is essential to teach young Great Danes not to jump up on people. Their size in a few short months can harm an adult person if left to do so. Don't wait until they are 6 months old or you will have trouble containing the head-strong personality.