Many of the behavioral problems between species occur because the two species signal their mood or intent in different ways. Horses are wonderful at picking up subtle nuances in our body language because that is how they communicate with each other. If we appear to be behaving submissively they are liable to be more confident or in some cases aggressive. If we appear too dominant, a self-assured horse may decide to display his position to us. If our posture doesn’t change this has the potential for leading to an aggressive standoff or escalation. Given that even the smallest pony far outweighs us, getting into a battle of brawn with a horse is never a good idea.
Much of what we perceive as aggression may just reflect a lack of education.
Physical Clues to Horse Aggression
The horse is superbly equipped for visual communication, which is probably the primary mode of expressing his feelings. The first clue to his level of excitement comes from his posture. In most situations either both his head and tail will be up or they will be down, rarely do the two extremes of his anatomy move in opposite directions. With increasing excitement both head and tail tend to become higher. The submissive horse has a lowered head and tail, and he will seem to be trying to slink along as low to the ground as he can. The more aggressive and dominant he feels the higher the tail and head will be carried and the more confident he will appear. A somewhat elevated head with a tucked or partially raised tail may accompany a defensive threat. However, a sleepy horse will drop his head and tail, while a horse that is excited, eager to check out a new environment or one that is moving at a faster pace than a walk will also have an elevated head and tail carriage, so context is also important in judging posture.
The next set of clues to a horse’s mood come from his facial expression, particularly the movements of his ears and his mouth and nose. There are thirteen pairs of muscles adjusting the position of each ear, and ten pairs moving the nostrils, mouth and lips. The aggressive horse’s ears are laid back against its head pushed hard against the skull. Eyes will be wide open and generally focused on the object of aggression, the body of the horse lining up to follow the forward facing eyes. The nostrils will also be dilated drawing in air in case the horse is called upon to take further action, they are drawn back so there will be wrinkles in the upper edge at the back. The mouth may be open and if he intends to bite or threatens to do so the incisor (front) teeth will be seen. If a bite or bite threat is being made the head will drop and be extended – giving the neck a snake like appearance. The submissive horse’s ears tend to spread out to the side or they are held backwards but not pinned against the head. In young horses in particular a behavior that is usually described as jaw snapping or Unterlegenheitsgebärde signals submission. The head is extended with the mouth open and the lips drawn back. The jaws are then opened and closed usually without the lips or teeth making contact. There may be a slight sucking sound as the tongue hits the roof of the mouth. This appeasing behavior has been variously described as either a ritualized grooming or eating display, both of which could be construed as calming, non-aggressive gestures.
The tail can also tell us a lot about a horse’s intentions. The dock of the tail is tensed in the aggressive horse so that the tip of the tail flows further out behind as the tail itself is raised. If the horse is slashing its tail forcefully from side to side, or even more dramatically up and down too, there is a good chance he will kick or lash out. This contrasts to the more leisurely tail swishing associated with brushing off flies.
Other signals that can help us judge a horse’s intentions would include the way he orients his body. If he turns his quarters towards the object of his attention, or pushes at it with his shoulder this would indicate either a dominant display or mild aggression. A submissive horse will try and scoot its lowered quarters away from the other animal or human. The tail will tuck under and the hindquarters will drop, while the head will deflect to the side so he is not looking directly at the other animal. If possible the horse will probably try to back away slowly. As aggressive displays increase the horse will mime biting – a head swing with the neck extended and a slightly opened mouth or nipping towards the adversary, usually aimed at the forelegs, head, shoulder or chest; striking – one or both forelegs lift off the ground or the feet are stamped hard on the ground; or kicking – vigorous tail switching accompanied by lifting one or both hind legs and extending them out behind. At this level it is clear from the lack of effort behind the motion that the movements are threats rather than intentional attacks. As antagonism increases these movements will become more forceful. In general, auditory behaviors tell us more about the level or arousal/excitement of the horse and less about his aggressive tendencies. Certainly high pitched squeals may accompany aggressive displays or attacks, while throaty low pitchednickers would be more appropriate for the horse that wishes to appease others.
Teaching Foals to Not be Aggressive
Horses need to be trained from their earliest interactions with humans to respect our space and accept our leadership. This is particularly important with orphaned foals. While their bumping and jostling us, mouthing or even nipping may seem cute when they are tiny, they will not be appropriate when the horse is older, and they will be much harder, or in some cases impossible, to eliminate. Kind but firm handling of foals is appropriate.
Some people advocate imprint training as described by Robert Miller DVM in his book Imprint Training of the Newborn Foal. Certainly getting a young foal used to being handled all over, accustomed to having his body manipulated and to strange sights and sounds at an early age will make these experiences easier for him when he is older. He should remain relaxed and cooperative for these exercises. Any resistance on his part should not be bullied into submission, but shaped gradually. Whether it is essential that these exercises are done immediately at birth, or whether they can wait for the succeeding days has been much debated. Provided they are completed in a timely fashion and the mare is not disturbed by human intervention, performing this program immediately after birth appears neither to prevent the foal receiving sufficient colostrum, nor the formation of an appropriate maternal bond.
Owner Actions That Can Trigger Aggression in Adult Horses
With older horses certain interactions with humans tend to be more likely to produce aggressive responses. Often these reflect lack of preparation or warning to the horse so that it is taken by surprise.
Things which often result in handler directed aggression include:
- Grooming – particularly sensitive spots with harsh implements
- Girth tightening – this may be because it is rushed all at once, the horse has been punched in the belly, or skin and hair caught and pulled in the past, in general fearing that their saddle might slip most riders tend to err on the side of over rather than under tightening girths
- Entering the stall – the owner may be pinned against the wall, or the horse turns its hind quarters to face the owner as she enters
- Striking or yelling at the horse, or acting in a manner the horse perceives as aggressive/dominant
- Handling feet and legs
- Syringe use and other potentially painful procedures
- Approaching the horse at pasture
- Cornering a horse
- Trying to coerce a horse to go somewhere – for example onto a trailer – it fears
- Leading a horse that has not learned to properly respect the handler, so it becomes distracted, shies, bolts or otherwise invades the handler’s space – horses that are fine at home may become liabilities when taken to more exciting venues such as shows.
Horses may aggressively demand treats and bite and nip if they are not delivered promptly. Hand feeding is not the problem, the problem arises because the horse has been permitted to get away with this behavior, and even rewarded for it in so far as it results in the owner swiftly coughing up the treat to ward off attack. Other horses nip owners for attention. They cannot distinguish between biting on thick winter clothing and on bare summer arms, so this behavior should never be tolerated and allowed to become established. In general, when designing a behavior modification program for human directed aggression in horses it is important to establish whether the behavior is motivated by fear or dominance.
By Linda Aronson, DVM, MA