Dogs love us unconditionally, and they are usually not shy about showing their affection. A happy dog shows a variety of signs, from a tail wagging and licking, to docile behavior. Learning to read your dog's body language will help you tell when he or she is happy, as well as when they aren't 100% happy.
Body language
A happy dog will show emotion throughout his body, from the brightness of his eyes, the wagging of his tail, to wiggling of his whole body, playful jumping and a smiling mouth.
Invitation to play
While a frightened dog may howl and hold its tail between its legs and bow submissively to you, a happy dog will jump and wag its tail to invite you to play. He can jump excitedly on his hind legs to get your attention and show that he is eager, happy, and ready to interact. This behavior may include short, high-pitched barks, or beeps and vigorously moving back and forth in front of you.
Rubbing belly
A happy dog will roll on his back and show you his belly, a sign that he is happy and trusts you. Reward the dog with a nice pet, which will increase his happiness. In fact, a dog who initiates physical contact, such as bumping into you while putting his muzzle or paws on you, expresses his happiness and desire to be with you in such a way.
Quiet times
A happy and content dog can show how he feels by just sitting or lying quietly next to you or with his head on your lap or with his body close to yours. This is his way of showing relaxed happiness and simply enjoying your presence. The more quality time you spend with him, the more signs of this happiness he will show.