Herd Instincts: Sparring

My horse was seen biting another horse in the throat. They were up on their hind legs supposedly playing when all of a sudden my horse made a very unusual move, according to the witness, and bit the other horse in the throat. The other horse ran and hid. The next day my horse was put out with three other horses, and two came back in with throat bites. All of the bites broke the skin leaving swelling. In one case the skin was torn.

Last month, there was a mysterious case where my horse's buddy came in from turnout with a severe bite across his throat. It was so bad a veterinarian was called on an emergency basis. Now, everyone is saying it had to have been my horse, and I must have missed it. My horse has been separated from the herd and put in a small penned area.

My horse is a 6-year-old Quarter Horse who was gelded two months shy of his fifth birthday. He was a stallion brought up on a Texas ranch. He ran with 20 other stallions when my trainer bought him, and he was not trained. My trainer started training him, and all the while he was still playing with young stallions on the ranch.

He spent most of his time with stallions. After he was gelded, he still went out with an older stallion in the pasture. I bought him right after he was gelded in June 2005. He was trained for a year in Texas, and I just got him back in June 2006. He is now at a public barn in Ohio, which has been a big adjustment after coming from Texas. However, he has never been an aggressive horse. He is generally peaceful with a kind eye, but he holds his own in the pasture.

He has been in a 3½-acre field with 12 other horses. There have been four new horses introduced to the field in the past two months.

I am really desperate for help and don't know what to do. No one--including my trainer--has come across this before. My horse can't just be penned up alone without any social contact, but we don't want any more horses hurt. Is this a killer instinct of "going for the throat?" Is he dangerous? Please let me know what your next steps would be.      Joan Starkowsky, Ohio

I'm so sorry for your situation. I have heard of this before, although only once or twice that I can remember in 25 years of observing horse behavior. I don't know why these rare cases occur.

As you know, most horses do not "go for the kill" with their herdmates with whom they normally get along, but stop short of serious injuries during sparring. And in general my experience has been that colts and stallions with experience running together have learned these sparring rules of limited aggression very well, better in general than horses with less intermale social experience.

You asked what my next step would be. Separation from other horses seems like the best solution under the circumstances. Perhaps your horse could be confined along a safe fenceline or in a round pen within a pasture of horses where he can see other horses, but not have direct contact.

You might also try a soft rubber grazing basket muzzle that would prevent your horse from biting. I would use one of the soft rubber ones that would not be a weapon in itself. My guess is that with impaired fighting tools, he might just not be as likely to engage in rough and tumble activity that has a chance to escalate. And I also would guess that there is the chance that if he can't effectively bite, he might still escalate his battling beyond where he should, but using alternate weapons. For example he might start seriously kicking herdmates. So if I were to try that, I would observe him for many hours to try to assess where he will go with that.

These grazing muzzles are meant to be worn at pasture, but if he does continue to engage in sparring, the muzzle might be a bit of a problem. His sparring partners might grab it and even pull it off.

It might be tempting to try to pasture him with a stronger male, say an intact stallion, if that were an option. The hope would be that the stronger male would teach him the limit.

My concern would be that your gelding might not recognize the limit and might escalate the battles and get hurt or killed. So it would be difficult to try that approach.

If this were my horse, I would likely just keep him physically separated from direct contact with other geldings for a couple of years at least.

If none of his targets have been females, it might be worth trying to pasture him with mature mares. Otherwise, I would try to get him fenceline exposure to horses as much as possible.

Your gelding is at that age where males are most playful. He might just mature out of this tendency somewhat in a few years, and with another group, when he is more mature, he might be less likely to bite.

If I did try grouping him with other geldings again sometime down the road, I would start by using the grazing muzzle and carefully observing them.

Finally, I must mention that I would also have moderate concern that a horse with this history might go after people in the same manner under certain circumstances. I have known a couple horses with atypical interhorse behavior that sometimes did "their thing" to people as well. A fairly common example is the horse with a short fuse for turning butt and kicking out at herdmates. Sometimes those horses will do the same unpredictably to people.

So if your horse ever tried to lunge toward a person as if to bite, I would expect him to repeat the behavior, and so I would take no further chances.

About the Author

Sue McDonnell, PhD, Certified AAB

Sue M. McDonnell, PhD, is a certified applied animal behaviorist and the founding head of the equine behavior program at the University of Pennsylvania's School of Veterinary Medicine. She is also the author of numerous books and articles about horse behavior and management.

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