Q.My horse, Leo, has been boarded at the same facility and in the same stall for the past year. He has been happy and relaxed and loves it there. However, starting two weeks ago, when he is brought into his stall in the evening (he is on day turnout) he has started to pace and dig large holes. This is not behavior that is at all characteristic of him. He is still completely happy and relaxed in turnout and when riding, pretty much anywhere except for in his stall. We tried a different stall for a night and he exhibited that same behavior. I am at a loss as to what could have caused it or how I can help make it better. Do you have any suggestions?

—Lisa, Lexington, Kentucky

A.It is difficult to make suggestions without much more information about Leo’s history and management. I would recommend having an in-depth consult with an equine behaviorist to help you figure this out—either an Animal Behavior Society-Certified Applied Animal Behaviorist or a veterinarian who is board-certified in behavior and experienced with horses.

Pacing and especially digging indicates that Leo is considerably stressed over something. Examples I have known over the years of sudden onset of this type of behavior in a previously comfortable environment were mostly social stress associated with changes in stall arrangements, etc., which I imagine you would have recognized and mentioned in your