If a 30-year-old horse appears happy, there's no reason to expect that to change until he develops a physical or social discomfort. | Photo: iStock

Q.My senior horse is 30 this year. Overall, he’s a healthy horse with minor issues (I have him on a pellet diet because of dental issues). My biggest concern is his mental happiness as his body deteriorates. Do you have any tips on keeping senior horses happy?

—Ashley, via e-mail

A.What a great question. I don’t know of any research on changes in horses’ mental comfort or what we might interpret as loss of happiness in horses of advanced age like we think of in some people of advanced age, so I can only answer from