If you have a big breed dog like Chico, its important to start training when they are young. If your dog is overpowering you try taking your dog for a walk or run before you start your training session. If you are picking out a dog to adopt try gently placing the dog/puppy into the down position to evaluate how dominate the dog/puppy is. Check with the owner of the dog first to get some basic information about the dog. if the dog puts up a lot of resistance then don't press the issue as you don't want to provoke aggressive behavior. When in doubt give me a call and I can help you out. You want to make sure you get the right dog for your lifestyle.