Question: what are the signs that a dog is happy?
Answer: His eyes and eyelids are relaxed, he blinks a lot, his gaze is soft and his brow is smooth. ... 
She's holding her body in a relaxed posture versus a tense or stiff stance. ... 
He has no destructive behaviors, even when he's home alone. ... 
She loves to play. ... 
He's belly-up and tongue out.