How do animals define happiness? For cats, is it being able to go outside, or being confined to an inside-only life? For dogs, is it daily walks and lots of toys or being able to lounge on the couch all day? For horses is it large paddocks and acres of turn-outs or small stalls and someone who cares for them every day?
Animals have a gift for adjusting to the conditions of their lives, seeking happiness rather than discontent no matter what their circumstances may be. If there is one overwhelming and common ingredient I have found in the lives of those animals who are the most happy it is this: they are loved by their humans. They are cherished for who they are and they are told daily how wonderful and important they are.