Playing Tug With Your Dog Will Make Him Aggressive
Most dogs treat tug as a cooperative game – it’s no fun unless both parties have hold of the toy. And you can use tug to teach your dog to be super careful with his teeth (game ends if teeth touch clothes or skin! Too bad!). To let go of something on cue. To wait till you give permission to grab the toy again. And to respond to your cues even when excited, excited, excited.  However, playing tug without set rules can crank up an excitable dog till he’s out of control. And it’s unwise to play tug with a dog who has certain behavioral problems – for example, possessiveness over toys.  Tug of War in and of itself, however, does not condition your dog to be aggressive.

A Wagging Tail Means A Happy Dog
Just too simple to be true. Not only does your dog use tail movement to signal a variety of moods from jolliness to stress and tension, but also she uses more than one body part at the same time to communicate her emotions and intentions. To understand what you are dog is communicating, you need to look not only at the tail but also at ear position, head position, eyes, and overall body posture. For example, a wagging tail at half mast together with loose body language – often the butt wags with the tail – is friendly and relaxed, but a stiffly wagging tail held erect and coupled with slow deliberate body language indicates a high degree of tension and is NOT an invitation to come closer or interact with the dog.