Question: I read your article about “Introducing horses”.  I would just like to ask your advice.  I have a mare (12) and a gelding (24) who have been together for a year and a half now.  The gelding is used for lessons but being as old as he is, I needed to buy another school pony to take the workload off him.  I had leased another gelding a while ago but my gelding just would not accept the new
gelding.  He constantly went for the new horse.  I introduced them all slowly and in their own paddocks but when it came to putting them together, it was an absolute mess.  I had to give the new gelding back.  I have now bought a young mare for the school and already he is going for her over the fence!!  Please could you give me some advice.  I really don’t know what else to try.  I’m desperate to get them together as my 12 year old mare is leaving soon and I don’t want any horses to have to stand in separate paddocks.  I only have limited grazing so I need them to be in one paddock while the other two paddocks rest.
Thank you so much for your time.

Answer: Thank you for reading my previous article. Horses are social animals that live within an organized social hierarchy. While most horses settle in together within a few days, the process is sometimes prolonged by horses with particularly aggressive natures. If you do not have large paddocks with adequate space for your horses to sort out their differences, and have to remove one from the pasture, the process can take even longer. If you have more than two horses, it often works well to take out the most aggressive horse and let the new horse bond with the other(s) for several days. In your particular situation, I find it interesting that your gelding is behaving the same way with a new mare as he did a gelding. Often times geldings who have been with a particular mare (or mares) will act protective of their “harems” toward other geldings, but this behavior is less often seen toward new mares. Usually same sex aggression is most often seen in newly introduced horses (i.e. mares are more aggressive with new mares and geldings are more aggressive with new geldings). Of course, there is no hard and fast rule for every horse or situation.

Perhaps one or more of the following suggestions will ease the transition of your new mare into the herd. First of all, can you stable your gelding while your mares are out together in the pasture for a few days? I am a firm believer in leaving horses out 24 hours a day, 7 days a week if at all possible (with shelter available, obviously), but in this situation, removing the problem gelding will allow the other two horses to get to know one another. Removing the gelding will allow the two mares to bond somewhat, and may make your gelding more accepting of this new mare when you do introduce him to this new party of two. Another option is to simply put the three horses out together (make sure your fencing is strong and your paddock is adequately large), and just let them sort it out. If your gelding does not try to run the mare out of the paddock and through the fence, run her continuously for hours, or otherwise cause serious physical injury to her, the horses will most likely sort themselves out in some sort of pecking order in short order.

Try to eliminate possible areas of conflict prior to turning the horses out. Ensure that the horses have adequate space for determining their new hierarchy. There is bound to be kicking, biting, and possibly some chasing, possibly for the first hour or so. Most horses don’t waste a lot of time (and therefore energy) on the herd hierarchy once it has been established. Also, be sure to provide several extra piles of hay if you feed hay in your paddocks, and an extra water source if your gelding tries to prevent the new mare from accessing the water trough. Don’t introduce the horses during feeding time or before feeding time. Instead, plan your introduction for at least an hour or so post grain feeding time during a part of the day when the horses might often be seen simply grazing or dozing in the pasture. And, also, while I don’t suggest leaving your horses alone, I do suggest that you stay out of the pasture and not interfere while the herd hierarchy is being determined as long as none of the horses are sustaining serious injuries. Removing the submissive horse or the aggressive horse in this situation may just make matters worse and make tempers flare higher next time you try the introduction. If you do not have adequate space to allow the horses to reach a new herd hierarchy, then you will have to plan on keeping one horse stabled while the other is in his/her paddock, or keep them in separate paddocks. Good luck!