Sherri,
While the behavior you describe could be chalked up to normal herd behavior, some horses can be classified as bullies. These horses are unnecessarily aggressive towards others. In other words, even after dominance has been fully established, they continue to attack other horses around them—seemingly for no good reason other than just to pick on them. If the gelding is not doing anything to deserve these attacks, then I’d say your mare is a bully.
You are absolutely correct in that this behavior poses not only a safety issue for you and your husband, but also for the gelding. One thing to think about is whether or not this is primarily happening when you are in the pen with them. It is possible that she is very jealous and is trying to keep him from coming near you. This is not necessarily a good thing either because it could indicate that she thinks you are her property—so it could indicate a dominance issue between you and your horse.
In answer to your second question—will this lead to her kicking you—I’d say that is doubtful. It sounds like she knows how to act properly when she is haltered or tacked-up but I’d make darn sure she is harshly punished if she even thinks about displaying any type of herd behavior toward another horse when she is in-hand or being ridden. This is absolutely forbidden behavior and should be met with a zero-tolerance policy. There are several articles in my Training Library on this subject.
When you enter any pen of horses, the pecking order should immediately change to where you are the alpha in the pen. One thing you might consider is to go into the pen with a stick or whip (for your protection—not to beat on the horse with) and actually defend the gelding, by chasing away the mare’s attacks. This will only help him when you are present but it may help resolve the dominance issues that may be under-lying between you and the mare.
Good luck and be safe!
Julie
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