By right, dogs are pack animals, and as such must be able to communicate their intentions effectively, so as to avoid misunderstanding and unintended conflict. All breeds of dogs share the common language which is Doggy Speak. They communicate in far more ways than some might give them credit for: They do not just wag their tail - their posture, ears, teeth and eyes all communicate certain feelings as well.
The most important part of your dog's body language to understand is whether it is acting submissively or dominantly to you and your family. Of course, it should act submissively - it should know that you are the leader and that is it simply a pack member - and dogs acting dominantly could be uncontrollable or even dangerous.
When Your Dog is Happy
We all identify with a wagging tail. However, there are other ways to know that your dog is content. Bright eyes are a sign of contentment, as are relaxed lips.