A happy, relaxed dog will wag their tail. The tails waves gently and loosely rather than stiffly.
Dogs that are content tend to have a relaxed posture, without tense muscles. They may lay on their side or back.
Happy dogs have soft, squinty eyes. Their eyes are calm rather than wide-eyed and stressed.
Dogs often play when they are in a good mood. Playing with toys, running around, and gentle mouthing are signs of happiness.
Dogs seek out affection from their owners when they are happy. Nudging hands for pets and leaning into cuddles are good signs.
When your dog's ears are up and forward, it is a sign they are engaged and content with their current situation.
Gentle licks on hands or faces are a sign of affection. It's your dog's way of giving you a "kiss."