Often dog owners do not recognize that their dog is dominating over them. The dog's wish is the owner's command.
Ex: It's bed time and your dog jumps on the bed to go to sleep. He decides he wants to lay between you and your partner. You decide that's not what you want and try to move him. As you are trying to move him, he growls at you. You decide you aren't going to move him because you don't want to bother him anymore. Your dog just gave you a command and you listened. He just showed you he was the dominant one. He showed you he was pack leader and not you.
There are several scenarios on how a dog can dominate you. If your dog alters your original decision regarding him, he is dominating over the situation. Start showing him you are boss. Make him listen to your commands. If he doesn't like the commands, correct his behavior immediately. Remember, you are pack leader!