Q: Since our aged gelding died last year, we’ve noticed some behavior changes in one of our mares. She’s not the alpha mare, and she was more attached to him than he was to her. Before he died she had severe separation anxiety, was very nervous, and always seemed stressed out. We even had her on a calming supplement that seemed to help her relax a bit around potentially stressful times, such as farrier or vet visits. But now she seems braver, much more relaxed, and happier than when our gelding was alive; she hasn’t even needed the calming supplement. Can the death of one horse lead to a complete change in another’s behavior or “personality”?

—Rachel, via e-mail

A: Whenever a horse leaves a long-established group, the behavior of certain individuals and the group dynamics can certainly change in significant ways. It probably doesn’t matter whether the animal dies or just leaves the herd.

It seems that owners worry most that when one bonded partner leaves, the remaining partner will have a change for the worse. In many cases the remaining horse immediately attaches to another herd member or, as you have seen with your mare, there can be a change that appears to represent less dependence and greater confidence