My 11-year-old horse recently started biting at his sides—digging deep and mutilating his skin and hair coat. Before I bought him last year, he was gelded and was away from other horses during his healing time. That’s when this strange behavior started. When I purchased him, the former owner barely mentioned the behavior. He just told me if you rode him each day, he’d be too tired to bite his sides. At my place, we keep him turned out with a larger herd. He exhibits the behavior when he’s around his buddies—not only when he may feel lonely. The horse is so sweet to people. He’s kind and respectful. He’s just terrible to himself. What can I do to help him? Why is he doing this?
Bit To Pieces
Dear Bit To Pieces,
Horses that self-mutilate (bite at their own flesh causing open wounds) are generally either in severe pain or experiencing severe stress. Have your veterinarian evaluate your horse to rule out any pain that may be causing the habit. You may also consider having an equine chiropractor (a veterinarian specially trained in spinal alignment) check your horse’s back and range of movement. If you resolve the pain or take away stress, the behavior should go away. That sounds easy, right? However, I wonder if your horse may be hurting himself because of pain or stress he experienced in the past. He may have felt stressed and frustrated when he was isolated at another barn. That stress-time behavior may have become habitual—meaning your horse may not feel pain or stress now, but he has the undesirable behavior nonetheless. If that’s the cause, your horse may need some time to realize he no longer needs the stress-relieving behavior. An interesting note, some research indicates that self-mutilation is related to Tourrettes Syndrome in humans. That link may explain why some horses continue to harm themselves long after a prompt is present.
I have seen a handful of self-mutilators in my training career. I’ll never forget the little mare that had been in training with a brutal hunter-jumper trainer who rode her in draw reins with her nose cranked to her chest. She began to bite her chest while being ridden. Both sides of her shoulders dripped with blood at the end of every course of jumps. Eventually her owner figured out that she was in pain and under stress because of the trainer’s methods. The owner removed the horse from the trainer’s barn and the problem behavior went away. Unfortunately, that trainer is still in business—or so I’ve heard. The other horses I’ve known were stallions with exacerbating medical conditions that caused them great pain. When the horses were brought back to a healthy condition, the self-mutilation went away.
To stop the flesh-eating behavior, you can put a neck cradle on your horse to prevent him from reaching to his sides or legs with his mouth. A cradle is made with dowels strapped together and buckled around his neck when he is alone in his stall. Look for a cradle in any vet catalogue’s bandaging section. It’s not a good idea to have a neck cradle on your horse when he’s turned out with other horses—he won’t be able to turn away from dominant horses or defend himself. Other horses may also become tangled in the cradle. Keep in mind, this cradle can stop the behavior, but not the horse’s desire to self mutilate. It’s important to find a way to help your horse inhibit his desire while his body begins to heal.
Dr. Katherine Houpt from Cornel University has researched self mutilation extensively. In her book, Domestic Animal Behavior for Veterinarians and Animal Scientists she says “self-mutilation is a very common behavior problem. Although it occurs in both sexes, it is much more common in stallions. The behavior consists of biting at or actually biting the flanks or, more rarely, the chest. The horse usually squeals and kicks out at the same time. The signs mimic those of acute colic, but can be differentiated because self-mutilation does not progress to rolling or depression and is chronic. The cause of the behavior is unknown, but because it usually responds to a change in the social environment it is probably caused by sociosexual deprivation. Most breeding stallions do lead similarly deprived lives in that they are kept in stalls in isolation from other horses, particularly from mares, but do not self-mutilate. Castration usually, but not always stops self-mutilation.” I got my copy of Houpt’s book from Knight Equestrian Books by calling 207-882-5494.
It sounds like you’re on the right track when evaluating your horse’s psychological needs. You said you have him turned out with other horses. That social arrangement—much different than his sole time in a stall–may help the behavior disappear after he becomes more comfortable with the herd. If health problems have been ruled out, your best recovery bet is to experiment with different herd arrangements until your horse feels comfortable and realizes chewing on his sides isn’t necessary any more. I wish you the best of luck!
Until next time,