An Unhealthy Mind

Last revised April 18, 2017.

Not enjoying life: a polo pony wearing a Pelham bit with curb chain, snaffle rein, draw rein, standing martingale, and breastplate.1

Unnatural Horsemanship

Once upon a time, someone captured a wild horse and succeeded in riding her or milking her. Eventually, humans figured out how to breed horses. The horses that prospered in the relationship were those who were quickest at habituation — the diminishing of a physiological or emotional response through repeated exposure. Over generations with humans, the horses that survived were successively less skittish, less nervous, more relaxed when confronting new sights and sounds. These horses were the bravest of the band. Today’s horses can handle scary stuff a lot better than yesterday’s. In fact, they seem to be able to endure almost anything. Perhaps, though, our breeding has gone too far. No one who climbed on a feral mustang would claim that it was lazy. Only the dull horses at the barn, those who’ve had the shit kicked out of them again and again, are called lazy.

Much of what we demand of our horses is challenging, running counter to their natural behavior. The challenges of unnatural horsemanship affect all ridden horses, regardless of setting: trail ride, obstacle course, eventing. The challenges below, adapted from McGreevy and McLean (2007),2 are all unnatural acts:

  • Social challenges include leaving the social group, taking the lead in the company of established leaders, being close to aggressive horses, walking abreast rather than trekking in a line, and ignoring displays by other horses.
  • In-hand challenges include leading/following handlers, lunging, entering small spaces, including trailers, proximity to humans, standing on moving platforms, and approaching erratically moving/sounding unfamiliar objects.
  • Under saddle challenges include walking, rather than running, through unfamiliar creek beds, overhanging elements, and approaching erratically moving/sounding unfamiliar objects, maintaining speed while traveling from light to dark areas or across uneven terrain or downhill (head is usually lowered to assist detection of the safest path), maintaining a fixed postural outline while changing gait, advancing when familiar horses are emitting fearful signals, and walking backward for more than a body length (i.e., entering any unfamiliar cul-de-sac that would require reversing).
  • Comfort challenges are those that prevent the horse from acting to increase its own comfort, and decrease its discomfort. They include not rolling when hot and standing in water, walking on stony ground, standing square for extended periods, the presence of a bit, and living with a sweaty head covered with a bridle and back covered with a girth, saddle, and saddle pad.
  • Environmental challenges include leaving the home range, deviating from an obvious track, and traversing, rather than avoiding, obstacles.

As they were evolving, horses was not preparing for life in a stall or paddock. Today’s horses do not find themselves in the conditions they are best designed for. A stall, in which a horse is unable to make contact with other horses, is far from his natural desires. A paddock or small fenced pasture, is not where he wants to spend his days. The stable isolates the horse, restricts his ability to detect an approaching predator, and prevents his escape. It restricts the time he can spend foraging.

Compounding the unnatural challenges that today’s horse must face are the challenges of poor training technique. Inappropriate punishment is common. Every issue of the mule magazines seems to have a joke about hitting a mule on the head with a 2×4 (har har har!). The planet has too many angry men with their belt buckles and boots, dominating horses through violence. Bits and spurs and whips are common, and called “aids” by the ignorant. Horses are “rewarded” with pats on the head and neck, even though when horses groom each other, they never pat, and never go for the head. And few horse trainers carry a supply of carrots to reward Mr. Horse when appropriate.

The Round Pen

The horse whisperer takes Mr. Horse to the round pen, where he is driven in one direction, then another. The horse eventually turns an ear to the trainer, licks, chews, and stretches his head forward and down in submission. The trainer drops his arms, and the horse comes to a stop, turns, and walks toward the trainer, If the trainer is not satisfied with this response, it is more laps for Mr. Horse, until he accedes to what the trainer is looking for. Each time in the round pen, the trainer repeats his arm waving in the center. With each lap, the horse realizes that all the trainer is looking for is submission, and so with each ordeal, he takes fewer and fewer laps before he turns and comes to the trainer.

If horses could talk, they would surely tell you that they don’t like to run. They don’t like to be scared. And they don’t know why this guy is waving his arms. So as soon as they can manage, they habituate to the waving arms of the natural horseman, and come up with a plan for coming to a stop. They discover that if they walk toward the trainer, the chasing will stop, and they will not have to run any more. As the trainer walks around in the round pen, the horse sticks with his discovery: stay close to the trainer, and you’ll be out of trouble.

The trainer is not quite as smart as he thinks. He forgets that if he did this to the horse without the round pen, it would be on the other side of the arena, or the field, or the county. He assumes that because the horse came to him in the round pen, he will come to him from the pasture, and so returns this educated horse to his stall.

After paying a trainer $500 for 10 lessons chasing my mule in the round pen (having “caught” him in his stall), this trainer needed to catch him in his pasture for a lesson. The trainer spent nearly two hours, with a grain bucket, trying to catch that wily mule, and failed. Some trainers don’t seem to understand that a horse does not like to be chased, and that chasing a horse in a round pen is aversive. They don’t understand that the horse is always looking for a way to avoid unpleasant situations, and the trick in the round pen is to stop running and walk over to the trainer. Some trainers don’t understand that they are aversive, and that in a field, a horse will find a way to avoid the unpleasant trainer by simply walking off, and staying beyond reach.

A trainer will tell you about respect and leadership. But he will not be able to tell you how the round pen works. I can tell you. It doesn’t work. Spend 100 hours in the round pen with your horse, then turn him out in the pasture, walk around the corner and come back to the pasture gate. Is he there, waiting for you? Nope. With most trainers, a horse’s time in the round pen is not pleasant. It is aversive. The last thing the horse wants is to spend one more second in “training”.

How can I be so cocky? I’ve seen it. I’ve done it. And I’ve read about it. Konstanze Krueger has done an important study of horses in the round pen,3 and finds “the time till horses follow the trainer decreases when the [round pen work] is repeated, and horses appear to generalize from the first trials to interactions with other trainers and slightly changed conditions. However, horses neither show following behavior in a large pasture nor on small paddocks, regardless of whether they are kept in social groups, in pairs or individually.”

The problem is not with the horse. Horses will generalize from one trainer in the round pen to another, and from one round pen to another. But in the round pen, they can’t get away. In a paddock or pasture, they can.

A trainer may tell you about the importance of pats or petting or grooming as a reward. After coming to a stop after laps in the round pen, such a trainer will deliver some pats or pets. Wasted energy, in most cases. Krueger’s round pen study I cited above4 found no significant effect of grooming on following either in the riding arena or in the field. More science and less blather would improve training and learning in the horse world.


Monty Roberts has produced a trailer loading video in which he shows off his “Dually Halter.5” He gets a reluctant horse to load into a big trailer in four and a half minutes through a combination of tactics:

  1. The halter is his special design, and when tension is added to the lead rope, a nose band pulls tight, crushing the horse’s delicate nasal bones.
  2. A chute is placed at the back of the trailer. Once in the chute, the horse can move forward or backward, but not to the side.
  3. An assistant stands behind the horse in the chute, closing off that escape route.
  4. Monty faces the horse, and uses advance and retreat.6 Facing the horse, he approaches it, and the horse backs up (in fear?). Then Monty backs up, dragging the horse forward. The horse learns that backing out of this mess won’t work, that standing still won’t work, but that moving forward will take some of the pressure off his nose.
  5. During this project, the horse has been facing the inside of the scary trailer. The increasing familiarity of the inside of the trailer makes it less intimidating.

Monty calls this his “gentle Join-Up® method”, but from the horse’s point of view, there is nothing gentle about it at all. Monty sells a lot of halters, but horses don’t buy them.

One of the problems with Monty’s halter is the same as the problem with most bitless bridles. A tug on the left rein will tighten the noose around your horse’s nose. If he doesn’t yield, or if he pulls away, the halter or bridle gets tighter. So he will cooperate with you, to try to avoid the discomfort. This is negative reinforcement. The problem is that the halter or bridle does not immediately loosen after he cooperates and you loosen the rein. Any delay in release makes the desirable response which he just gave less likely, and thus punish that response.7 Your efforts to lead cause discomfort, whether he complies or not. Such a simple act can help develop and maintain learned helplessness (see next chapter). Because of this, I now ride in a standard halter that has sheepskin padding added to nose and brow band. The halter never tightens, but I’m still able to signal turns and stops just fine. A horse who wants to please needs only a subtle signal to do what you’ve asked.

Scott Purdum also sells halters. The “Advantage Horsemanship Bitless Halter”8 is “Designed to teach a horse how to come off of pressure more willingly, making the horse easier to handle for the owner/rider; A thinner, stiffer rope used which makes it more uncomfortable for horses to lean on should they choose to; Knots on the nose band that act upon the pressure points located on either side of the horse’s nose; Twisted poll piece that makes the horse more responsive and is more uncomfortable for a horse to lean backwards on; Light weight so no unnecessary pressure applied when not needed” Sounds good. Looks good. Horses must hate it, because any small head movement can result in a knot jamming into a tender spot on Mr. Horse’s head. All of the tension on the rope, whether caused by your pull or your horse’s, is concentrated on a small spot about half an inch in diameter.

What trainers everywhere must remember is that violence is not the only thing that horses find aversive. A trainer’s outstretched arm in the round pen is not violent, but it seems to be unpleasant for the horse. The special halter that crushes the nose, or one that puts all of your weight into a tiny spot on your horse’s face does not look violent when viewed from the bleachers. Advance and retreat technique are not violent, but they are unpleasant for the horse.

Giddy-Up Rope

While I’m at it: Monty’s Giddy-Up rope is to be swung rapidly by a rider between his legs while in the saddle — that is, just behind the horse’s forelegs. Monty describes its action: “This extrinsic training equipment works on the horse’s mind to motivate forward motion… The Giddy-Up introduces movement to the peripheral vision of the horse. This movement will be perceived by the horse to be dangerous, and yet no pain comes of it. The horse is likely to advance quickly, moving away from the perceived intruder.9” The thinking seems to be that physical pain is not good, but terror is OK.

I have no doubt that all of this stuff works. But I think a better name for such training might be “My way or the highway.”


Life in a stall or small paddock? Not a pleasant idea if we were talking about a human life.

Stallions are especially likely to be confined to stalls. Because they are such dangerous, savage beasts, they cannot be trusted to be with other horses or even to be ridden, and so must be kept locked up. That’s the myth. The facts are otherwise. Studies show that in both feral and domesticated bands of horses, stallions are neither the most dominant nor most aggressive animals, and that bands are typically led by mares.10

Keeping a stallion locked up can transform him into a dangerous, savage beast, fulfilling the prophecy.11 I know a stallion that was purchased for a 12 year old girl for $20,000. She was afraid of him, and he spent his next year locked in a “stallion stall” — a stall with extra bracing and extra bars. Light scarcely entered the stall. After a year of confinement, the family sold him for a dollar.

Does your horse like it? You can always open the gate to the paddock or door to the stall to find out. My horse will go in for the grain, maybe the peace and quiet. But 24 hours in a stall is too much. After about 12 hours, my horse begins to try to eat his way out.

Stables and stalls have been linked to various stereotypies such as wood-chewing, weaving, cribbing, and box walking. Dressage, eventing, and race horses may spend significant time in a stall. One survey of 1,750 horses found that the more time spent in a stall, the more likely a horse will show abnormal behavior and stereotypies12 — compulsive abnormal, rhythmic, repetitive, predictable, stylized and apparently functionless patterns of movement. In their earliest stages of development, they may show some variation in their moves.13 If you are reading aloud, “stereotypies” is pronounced “stereotype ease”.


You’ve probably seen stereotypies — persistent repetition of what seems to be a purposeless act — in tigers or other caged animals at the zoo: round and round and round on some particular route, never deviating, never stopping. Stereotypies can sometimes occur in a wide variety of species, including domesticated14 and captive wild animals, as well as in humans. In humans, we would call them obsessive compulsive disorders (if accompanied by obsessive/intrusive thoughts); horse owners often call them “vices” or “stable vices”. Because they seem so similar to the condition in humans, but because we can’t know what the horse is thinking, it has been proposed that they be simply called “compulsive disorders.15” In both humans and horse16 they may have great value in relieving stress.

In horses, stereotypies include locomotor stereotypies (weaving, stall digging, stall walking (stall circling), fence pacing, head bobbing, pawing, head shaking, weaving and wall kicking) and oral stereotypies (cribbing, wood chewing, flank biting, wind sucking, tongue playing, lip smacking, etc.) Locomotor stereotypies may be triggered when the food cart moves down the aisle in the barn, or when the horse is separated from others. Spontaneous erection and masturbation in horses are often considered stereotypies, but not by scientists: they are observed in confined, pastured, and free-ranging horses, in geldings and particularly all normal stallions, and so they are not “stylized” or “abnormal” at all.

Stereotypies may become simplified versions of the initial stages of more complex behaviors. For example, when a horse tries to get through a gate or out of its stall, its movements might initially be those of fence walking or stall circling. But over time the walk along the fence is shortened to pacing near the gate, and perhaps finally shortened to pacing at the gate. And the circled stall may transform to pacing back and forth on one side of the stall, and then, perhaps, to weaving on that side.

Many stereotypies seem to be an unreasonable extension of a reasonable idea.

  • A horse is added to a herd, and panics. He doesn’t want to be here. So it is natural that he run away. But a fence blocks his exit. So he keeps running, up and down and up and down the fence.
  • A tiger in a small outdoor enclosure doesn’t want to be there either. He needs to escape, and begins walking. He’d like to leave the county, but there is a moat, and he hates water… soon he fixes on a particular path around his cage, and walks it again and again and again.
  • Under some circumstances, a horse becomes very angry. He would like to target the source of his aggression, but that target is not present. So he engages in flank-biting and self-mutilation.

Propensity for Stereotypy

A horse’s demographics seems to be involved in stereotypies. In one study (Luescher et al., 1998),17 Thoroughbreds were significantly more likely to crib or weave than other breeds, geldings and stallions were more likely to crib or weave than mares, and the risk of being a cribber or weaver increased with increasing age. Arabians were more likely to engage in stall walking, and the risk of being a stall walker increased with increasing age.

Stall kicking might be affected by housing. In the Luescher et al study, 81% of stall kickers had the possibility for physical contact with horses in neighboring stalls, while only 35% of non-kickers had a chance for physical contact with neighboring horses.

Possible Causes

Stress. There can be no doubt that stereotypies are caused by stress.18 Hausberger et al (2009) have observed19although time spent performing stereotypies increases with time spent in stall20, it may also increase with time spent working.21 Stereotypies in thoroughbreds seem to increase around the age of 2, when training starts,22 whereas unbroken young horses show lower emotional reactions to a handling test than regularly trained show horses. McGreevy et al.23 observed differences in prevalence of stereotypies according to the type of work, dressage horses presenting the highest prevalence. These differences were attributed to differences in management practices. However different riding styles may impose different ranges of physical and psychological stressors on a horse24, that could explain these findings. Thus differences in the emotional reactions of horses (outside the working situation) in behavioral tests were observed according to the type of work.25 Dressage training where horses have to perform restrained gaits and present a curved neck have more physical (and psychological?) constraints than jumping where horses are allowed more extended gaits and less pressure from the rider. A recent study showed that the “rollkür” posture (extreme neck curving) associated with some dressage practices was associated with more tail swishing, mouth opening and fear reactions than was observed in other horses.26

Early Separation. In the wild, a feral foal won’t leave the band until he or she feels ready, at an age between 1 and 2.5 years.27 But raised as a “cash crop”, they are often forcefully taken from their mothers before this, and may be moved to a new facility, with nothing familiar. Studies of other animals have found that early separation leads to many problems, as well as affecting the likelihood for stereotypy.28

Confinement. A survey29 of 1,101 horse owners and their 1,750 horses found that confinement in a stall was apparently a factor in wood-chewing, weaving, crib-biting.wind-sucking, and box walking. Among dressage and eventing horses, the longer the time spent in the stall, the greater the chance of abnormal behavior. Endurance horses spent less time in stalls, and stall time was not correlated with abnormal behavior.

Genetics. Genetics may be involved in some stereotypies. A genetic component has been found in stereotypies in dogs and cats,30 cattle,31 and hens32. Researchers in Italy33 interviewed 80 trainers and learned about stereotypies on 1,035 Thoroughbreds. The incidence of cribbing, weaving and stall-walking in the horses was low: 2.4, 2.5 and 2.5%, respectively. But the incidence of these stereotypies in families that had one of these stereotypies was much higher than in the surveyed population: 30% for cribbing, 26% for weaving and 13% for stall-walking.

Unlikely Causes

Many believe that stereotypies are learned from others that exhibit the stereotypy, through mimicry. But there is almost no evidence that horses learn through imitation, and so it is likely that a single stress has affected all of the horses in the group, and the stereotypy is appearing in each as it reaches a point of being unable to deal otherwise with the stress. Horses face many stresses, but do not have many stereotypies to choose from.

Maintaining a Stereotypy

Stereotypies may produce neurochemicals (endogenous opiates) that reinforce and maintain it. An injection of apomorphine (an opiate) will trigger circling, pacing, and weaving in horses confined to stalls. Opiate receptor blockers will stop cribbing, but they are expensive and short lasting in their effects. But they prove the point: a stereotypy creates pleasure in the horse, and is self-rewarding.34 So a current stereotypy might not be the result of current stress or current confinement conditions, but of previous trouble. Once a horse finds a stereotypy pleasurable, he may continue it long after its original cause has vanished.

Intermittent reinforcement can maintain and strengthen a stereotypy. Stereotypies that have developed while waiting for the food cart will receive positive reinforcement when the food cart arrives. Pacing at a gate will receive positive reinforcement when the gate is finally opened. Placing feed in the buckets in stalls before the horses are brought in will reduce pacing in the stall, but may move the problem to the gate, as horses wait with increased eagerness for the chance to be let back into their stalls. Feeding them in the pasture might eliminate gate pacing, but might also make them harder to bring in at night.

There is now some evidence that some stereotypies are triggered by the presence of a human, and may not occur in our absence. It is possible that the human triggers additional stress, which triggers the stereotypy.

Not all Stereotypies have the Same Cause or Same Resolution

Both cribbing and wood chewing tend to begin when there is not enough roughage in the horse’s diet. But other stereotypies can come from an allergic reaction to shampoo, an ulcer, and other causes. I review some of the suspects below.

Cribbing is an oral behavior in which the horse grasps a surface with his incisors, arches his neck, contracts the lower neck muscles to retract the larynx. As the horse does this, air rushes into the esophagus making a grunting sound. Wind sucking is the same, but is done without grasping an object. Many consider it to be part of the cribbing mechanism, and to have the same cause and treatment. Very different factors may underlie cribbing/wind sucking:

  • Cribbing is often associated with stomach ulcers or colic, but all might derive from stress as a common cause. Do check for ulcers in any horse that has been cribbing.
  • Cribbing and wind sucking are sometimes found in horses that are confined in stalls and become bored. They are habits that are learned, may be rooted in a genetic predisposition, and may continue after the original root causes are removed.

Cribbing. 35

Good advice would be to remove the root causes of such behavior, and see what happens. Do this:

  • Turn the horses out into pastures where they can explore and romp. Minimize stall time.
  • Provide environmental stimulation of any sort: music in the barn, regular grooming, exercise, two meals a day instead of one, toys, etc.
  • Use a slow feeder — something like a bird feeder that the horse must work to extract a small bit of food. Let him work for his supper, but make sure he’s getting enough to eat.36 There is research that supports the notion that slow feeders reduce stereotypies.37
  • Ensure that the horses can get at each other to play and socialize.

If that doesn’t help, you might consider a modified dog training collar that can be remotely controlled to deliver a shock.38 Keep the collar on throughout the day, so that when you are present and deliver shocks, the horse doesn’t associate the shocks with the collar. And stand well away, so that he doesn’t associate the shocks with your presence. Be sure that the level of shock is something that you can tolerate on your forearm or neck.

Wood chewing (lignophagia) seems to stem from a diet that lacks roughage, and is associated with confinement, high-concentrate diets, and a lack of exercise and stimulation. It becomes more common in cold or wet weather, when horses spend more time in stalls. Turning the wood chewing horse out, adding roughage to his diet, and improving his social life can solve the problem. While a shock collar might help if those efforts fail, there is reason to think that wood chewing is a desperate attempt to obtain particular minerals, particularly those missing from the pasture in the winter.

Self-mutilation sometimes occurs, in which the horse bites himself in the flanks or sometimes the chest or limbs. It is more common in stallions than geldings,39 but affects mares as well.40 Sometimes the biting is a response to pain,41 a skin infection or allergy or hypersensitivity to a soap or shampoo,42 and should be treated by treating the skin. Sometimes, stress seems to underlie this stereotypy, and changing the horse’s social environment (such as removing mares from the sight of a stallion, removing other stallions from the horse’s daily life, or reducing isolation from other horses) often succeeds in stopping it. Sometimes, especially in stalled stallions, self-mutilation begins as self-directed inter-male aggression.43

Self-mutilation in response to an allergic reaction to a shampoo.44

Circling, weaving, and pacing are normal behaviors of normal horses, and should only be considered as stereotypies if they become excessive and replace normal periods of eating or resting. A caged tiger in a zoo has a good chance of showing one of these stereotypies. Horses stressed by restraint such as tying or confinement are the most likely to develop these stereotypies. A stalled horse that circles may eventually lose its stereotypy if hay is put in each corner of its stall, allowing it to stop in each corner for a snack.

Stall kicking may produce a satisfying sound to the horse, but it is not good for bones, joints, or stalls. Horses sometimes learn to kick or paw just before feeding time, and conclude that their efforts have brought on the food. (You might have concluded that if you board an elevator, and it does not immediately take off, a little bit of jumping up and down might change its mind. This is the same idea.) If kicking accompanies feeding, then give small amounts of feed only when the horse has not kicked, and gradually raise the time that the horse must stand quietly before getting the feed.

Pawing is normal, or can be considered a stereotypy if excessive. Excessive pawing is hard on the hoof, foot and the flooring. Pawing at feeding time may be normal, deriving from a horse’s stepping along in a pasture when grazing. But pawing can be shorthand for an effort to escape confinement or pain. Protect limbs and stall floor with heavy rubber matting, and increase turnout time to address pawing.

Side Effects

Little research has been done on the side effects of stereotypies — we’ve focused so much on fretting about how to cure them. But just as mental disorders in humans potentially have widespread effects, those in horses may too. There is some evidence that horses with stereotypies spend less time lying down and sleeping.45 Because this is the only position in which REM sleep occurs, stereotypies may be preventing this very essential sleep. Sleep deprivation in humans can interfere with memory46 and plasticity,47 and this may be the case with horses: there is evidence that horses with stereotypies don’t learn as well, and don’t perform what they have learned as rapidly.48

Preventing or Treating Stereotypies with Environmental Enrichment

Zookeepers have learned what prisoners have always known: life inside a little cage is boring. Life inside a big cage is boring. Life with enriching activities that challenge the mind can be quite interesting. Environmental enrichment — the improvement of enclosure design, and the use of feeding devices, novel objects, and appropriate social groupings to stimulate captive animals — reduces stereotypies.49

There are many ways that life in a stall can be improved.

Monotony. When they graze, feral horses eat many species of grasses and browse.50 But back at the ranch, domestic horses have few species to choose from in their pastures, and usually only one species of “hay” to dine on in their stalls. In one study, three researchers found that horses much preferred to have a variety of forages available in their stalls, and sampled from all of them.51 Another study52 found that with multiple forages (three long-chop and three short-chop commercially available forages) provided, stereotypic weaving did not occur, but it did occur when only a single forage (hay) was provided.

Low-forage diets. A monotonous low-forage diet — a diet in which a high proportion of intake is from concentrates and grain, and a smaller proportion from hay — in the stall has been linked to various stereotypies.53 There are good reasons to provide “high forage” diets and minimize the concentrated food and grain. Horses are adapted to browse and forage about 16 hours a day.54 Winskill et al (1996)55 cite studies of the effect of low and high forage diets on stereotypies. One reason may be that on a low fiber diet, a horse in a stall finishes his dinner and now has nothing to do.56 A horse with time on his hands may spend more time chewing wood and engaging in coprophagy than those fed hay.57 It is possible that it is not the extra spare time that a low fiber diet offers, but rather the lack of a grazing-like activity that underlies some stereotypies.58 In any case, environmental enrichment gizmos that stimulate foraging seem to help reduce behavioral problems such as coprophagy.59 Idle hands are the devil’s workshop.

There is another big benefit in providing high forage diets: besides avoiding the boredom that occurs when the horse finishes his meal in 10 minutes and now has nothing to do, the chance of gastric ulcers is reduced.60

Toys. It is a common belief that adding stall toys, reducing the amount of forced exercise, and increasing turnout should provide environmental enrichment and reduce the likelihood of stereotypies. But such enrichment is often offered after the stereotypy is launched: in one study,61 horses with these forms of enrichment were more likely to have a stereotypy. But correlation and causation are different beasts, and we don’t know if the enrichment was present before the stereotypy developed, and don’t know whether the enrichment reduced a stereotypy without eliminating it.

My personal opinion:

  1. Add stall toys, and determine if they are played with. Search with Google, or search on Amazon for “stall toys” — you’ll find plenty. You might find that your horse does not play with some toy, in which case it is just taking up space. You may find that he has destroyed it, or that it has rolled out of his stall. So a bit of monitoring is in order. My horse happens to love to play with his stall snack holder,62 and the wall of the stall is starting to wear where he has rolled it back and forth. My horse seems to like a rubber chicken (with a squeaker inside), a small traffic cone, and a glove. He’ll pick them up, squeeze them, shake them, and drop them (or hand them to me). Such toys are likely to roll out of his stall, so guard against this.
  2. Increase your horse’s turnout with one or more other horses. Just standing around outside is not much more interesting than standing around inside. But having someone to interact with can be a big deal: social stimulation and an opportunity for unrestrained exercise.
  3. Offer two or more kinds of forage, such as two kinds of hay, or hay plus beet pulp, or hay plus cubes. Your local farm store will likely carry a variety of products. You need not spend a fortune on this: you can limit the amount of the more expensive forage, and provide the cheaper one ad lib.
  4. Minimize use of concentrates.

More information

  • See “Behavioral Problems of Horses”, the Merck Veterinary Manual.63
  • A good review is provided by Katherine Houpt and Sue McDonnell.64


1 Image source:

2 McGreevy, Paul D., and Andrew N. McLean. “Roles of learning theory and ethology in equitation.” Journal of Veterinary Behavior: Clinical Applications and Research 2, no. 4 (2007): 108-118.

3 Krueger, Konstanze. “Behaviour of horses in the “round pen technique”.” Applied Animal Behaviour Science 104, no. 1 (2007): 162-170.

4 Krueger, Konstanze. “Behaviour of horses in the “round pen technique”.” Applied Animal Behaviour Science 104, no. 1 (2007): 162-170.

5 Roberts, Monty. “Monty Roberts Horse Trailer Loading”

6 See Blackshaw, J.K., Kirk, D., Creiger, S.E., 1983. A different approach to horse handling, based on the Jeffrey method. Int. J. Study Anim. Probl. 4, 117-123.

7 McGreevy, Paul D., and Andrew N. McLean. “Punishment in horse-training and the concept of ethical equitation.” Journal of Veterinary Behavior: Clinical Applications and Research 4.5 (2009): 193-197.

8 Bitless Halter Bridle.

9 “Giddy-Up Rope”

10 Houpt, Katherine Albro, and Ronald Keiper. “The position of the stallion in the equine dominance hierarchy of feral and domestic ponies.” Journal of Animal Science 54, no. 5 (1982): 945-950.

11 Goodwin, Deborah. “The importance of ethology in understanding the behaviour of the horse.” Equine Veterinary Journal 28 (1999): 15-19.

12 McGreevy, P. D., N. P. French, and C. J. Nicol. “The prevalence of abnormal behaviours in dressage, eventing and endurance horses in relation to stabling.” The Veterinary Record 137.2 (1995): 36-37.

13 Cronin, G. M., and P. R. Wiepkema. “The development and significance of abnormal stereotyped behaviours in tethered sows.” Ann Rech Vet 15 (1984): 263-270.

14 For a review of stereotypies in dogs and cats, see Luescher, U. Andrew, Donal B. McKeown, and Jack Halip. “Stereotypic or obsessive-compulsive disorders in dogs and cats.” Veterinary Clinics of North America: Small Animal Practice 21, no. 2 (1991): 401-413.

15 Luescher, U. A., D. B. McKeown, and Helena Dean. “A cross-sectional study on compulsive behaviour (stable vices) in horses.” Equine Veterinary Journal 30, no. S27 (1998): 14-18.

16 Houpt, Katherine A., and Sue M. McDonnell. “Equine stereotypies.” Comp Cont Educ Pract Vet 15 (1993): 1265-1271.; Wilcox, Sarah, Kimberly Dusza, and Katherine Houpt. “The relationship between recumbent rest and masturbation in stallions.” Journal of Equine Veterinary Science 11.1 (1991): 23-26.; McDonnell, Sue M., M. Henry, and F. Bristol. “Spontaneous erection and masturbation in equids.” J. Reprod. Fertil. Suppl 44 (1991): 664-665.

17 Luescher, U. A., D. B. McKeown, and Helena Dean. “A cross-sectional study on compulsive behaviour (stable vices) in horses.” Equine Veterinary Journal 30, no. S27 (1998): 14-18.

18 Mason G, Rushen J (2007) Stereotypic behaviour in captive animals: fundamentals and applications for welfare (2nd ed.). Wallingford: CAB International.

19 Hausberger, Martine, Emmanuel Gautier, Veronique Biquand, Christophe Lunel, and Patrick Jego. “Could work be a source of behavioural disorders? A study in horses.” PLoS One 4, no. 10 (2009): e7625.

20 McGreevy PD, French NP, Nicol CJ (1995a) The prevalence of abnormal behaviours in dressage, eventing and endurance horses in relation to stabling. Vet Rec 137: 36–7.

21 Christie JL, Hewson CJ, Riley CB, McNiven MA, Dohoo IR, et al. (2006) Management factors affecting stereotypies and body condition score in nonracing horses in Prince Edward Island. Can Vet J 47: 136–143.

22 Mills DS, Alston RD, Rogers V, Longford NT (2002) Factors associated with the prevalence of stereotypic behaviour amongst thoroughbred horses passing through auctioneer sales. Appl Anim Behav Sci 78: 115–124.

23 McGreevy PD, French NP, Nicol CJ (1995a) The prevalence of abnormal behaviours in dressage, eventing and endurance horses in relation to stabling. Vet Rec 137: 36–7.

24 Mills DS (2005) Repetitive movement problems in the horse. In: Mills DS, McDonnell SM,, editors. The Domestic Horse. Cambridge: Cambridge University Press. pp. 212–227.;  Ödberg FO, Bouissou MF (1999) The development of equestrianism from the baroque period to the present day and its consequences for the welfare of horses. Eq Vet J 28: 26–30.

25 Hausberger M, Bruderer C, Le Scolan N, Pierre JS (2004) The interplay of environmental and genetic factors in temperament/personality traits of horses. J Comp Psy 118: 434–446.

26 von Borstel U, Duncan IJH, Shoveller AK, Merkies K, Keeling LJ, et al. (2008) Impact of riding in a coercively obtained Rollkur posture on welfare and fear of performance horses. Appl Anim Behav Sci 116: 228–236.

27 Goodwin, Deborah. “The importance of ethology in understanding the behaviour of the horse.” Equine Veterinary Journal 28 (1999): 15-19.

28 Jeppesen, Leif Lau, Knud Erik Heller, and T. Dalsgaard. “Effects of early weaning and housing conditions on the development of stereotypies in farmed mink.” Applied Animal Behaviour Science 68, no. 1 (2000): 85-92.; Matthews, Keith, F. Scott Hall, Lawrence S. Wilkinson, and Trevor W. Robbins. “Retarded acquisition and reduced expression of conditioned locomotor activity in adult rats following repeated early maternal separation: effects of prefeeding, d-amphetamine, dopamine antagonists and clonidine.” Psychopharmacology 126, no. 1 (1996): 75-84.; Ridley, Rosalind M., and Harry F. Baker. “Stereotypy in monkeys and humans.” Psychological medicine 12, no. 01 (1982): 61-72.

29 McGreevy, P. D., N. P. French, and C. J. Nicol. “The prevalence of abnormal behaviours in dressage, eventing and endurance horses in relation to stabling.” The Veterinary Record 137, no. 2 (1995): 36-37.

30 Luescher, U.A., McKeown, D.B. and Halip, J. (1991b) Stereotypic or obsessive compulsive disorders in dogs and cats. Vet. Clin. N. Am: Small Anim Prucr. 21,401-413.

31 Sambraus, H.H. (1985) Mouth-based anomalous syndromes. In: Ethology of Farm Animals. World Animal Science, Series A. Ed: A.F. Fraser. Elsevier, New York. pp 39 1-422.

32 Wood-Gush, D.G.M. (1972) Strain differences in response to suboptimal stimulus in the fowl. Anim. Behuv 20, 72-76.

33 Vecchiotti, Giuliana Galizzi, and Roberto Galanti. “Evidence of heredity of cribbing, weaving and stall-walking in Thoroughbred horses.” Livestock Production Science 14, no. 1 (1986): 91-95.

34 Dodman, Nicholas H., L. Shuster, and R. Dixon. “Investigation into the use of narcotic antagonists in the treatment of a stereotypic behavior pattern (crib-biting) in the horse.” American journal of veterinary research 48.2 (1987): 311-319.

35 Image source:

36 Find a variety of slow feeders online. Here is one source:

37 Henderson, J. V., and N. K. Waran. “Reducing equine stereotypies using an EquiballTM.” Anim. welf 10 (2001): 73-80.; Winskill, Linda C., Natalie K. Waran, and Robert J. Young. “The effect of a foraging device (a modified ‘Edinburgh Foodball’) on the behaviour of the stabled horse.” Applied Animal Behaviour Science 48, no. 1-2 (1996): 25-35.

38 Baker, G. J., and J. Kear-Colwell. “Aerophagia (windsucking) and aversion therapy in the horse.” Proceedings of the AAEP 20:127-130, annual convention. 1974 or 1975

39 Dodman, N.H., Shuster L. Court, M.H. and Patel, J. (1988) Use of a narcotic antagonist (Nalmefene) to suppress self-mutilative behaviour in a stallion. J. Am. vet. med. Ass. 192, 1585-1586. ; Houpt, K.A. (1981) Equine hehaviour problems in relation to humane management. Int. J. Stud. Anim. Prob. 2, 329-337.; Luexher. U.A., McKeown, D B. and Halip, J. (1991a) Reviewing the causes of obsessive-compulsive disorders in horses. Vet. Med. 89, 527-530.

40 Dodman, N. H., J. A. Normile, L. Shuster, and W. Rand. “Equine self-mutilation syndrome (57 cases).” Journal of the American Veterinary Medical Association 204, no. 8 (1994): 1219-1223.

41 McDonnell, Sue M. “Is it psychological, physical, or both?.” (2005).

42 See the interesting video “Contact Hypersensitivity” Towcester Veterinary Centre Equine Clinic.

43 McDonnell, Sue M. “Is it psychological, physical, or both?.” (2005).

44 Image source: “Contact Hypersensitivity” Towcester Veterinary Centre Equine Clinic.

45 Hausberger, Martine, Emmanuel Gautier, Christine Müller, and Patrick Jego. “Lower learning abilities in stereotypic horses.” Applied Animal Behaviour Science 107, no. 3 (2007): 299-306.

46 Karni, A., Taune, D., Rubenstein, B.S., Askenasy, J.J., Sagi, D., 1994. Dependence on REM sleep of overnight improvement of a perceptual skill. Science 265, 679–682.; Peigneux, P., Laureys, S., Delbeuck, X., Maquet, P., 2001. Sleeping brain, learning brain. The role of sleep for memory systems. Neuroreport 12, 111–124.

47 Frank, M.G., Issa, N.P., Stryker, M.P., 2001. Sleep enhances plasticity in the developing visual cortex. Neuron 30, 275–287.

48 Hausberger, Martine, Emmanuel Gautier, Christine Müller, and Patrick Jego. “Lower learning abilities in stereotypic horses.” Applied Animal Behaviour Science 107, no. 3 (2007): 299-306.

49 See, for example, Carlstead, K., and D. Shepherdson. “Alleviating stress in zoo animals with environmental enrichment.” The biology of animal stress: Basic principles and implications for animal welfare (2000): 337-354.; Robinson, M. H. “Enriching the lives of zoo animals, and their welfare: where research can be fundamental.” Animal Welfare 7, no. 2 (1998): 151-175.; Swaisgood, R., and D. Shepherdson. “Environmental enrichment as a strategy for mitigating stereotypies in zoo animals: a literature review and meta-analysis.” Stereotypic animal behaviour: fundamentals and applications to welfare (2006): 256-285.; Swaisgood, Ronald R., and David J. Shepherdson. “Scientific approaches to enrichment and stereotypies in zoo animals: what’s been done and where should we go next?.” Zoo Biology 24, no. 6 (2005): 499-518.

50 Hansen, R.M. (1976) Foods of free-roaming horses in Southern New Mexico. J. Range Manag. 29, 437; Putman, R.J., Pratt, R.M., Ekins, J.R. and Edwards, P.J. (1987) Food and feeding behaviour of cattle and ponies in the New Forest, Hampshire. J. appl. Ecol. 24, 369-380.; Waring, G.H., 1983. Horse Behavior: The behavioral traits and adaptations of domestic and wild horses, including ponies. Noyes Publications, Park Ridge, New Jersey, p. 79.

51 Goodwin, D., H. P. B. Davidson, and P. Harris. “Foraging enrichment for stabled horses: effects on behaviour and selection.” Equine Veterinary Journal 34, no. 7 (2002): 686-692.

52 Thorne, J. B., D. Goodwin, M. J. Kennedy, H. P. B. Davidson, and P. Harris. “Foraging enrichment for individually housed horses: practicality and effects on behaviour.” Applied Animal Behaviour Science 94, no. 1 (2005): 149-164.

53 McGreevy, P.D., French, N.P., and Nicol, C.J. (1995) The prevalence of abnormal behaviours in Dressage, Eventing and Endurance horses in relation to stabling. Vet. Rec. 137, 36-37.; McGreevy, P.D., Cripps, P.J., French, N.P., Green, L.E. and Nicol, C.J. (1995) Management factors associated with stereotypic and redirected behaviour in the Thoroughbred horse. Equine vet. J. 27, 86-91.

54 Waring, G.H., 2003. Horse behavior. Noyes Publications / William Andrew Publishing, Norwich, England, p. 292.

55 Winskill, Linda C., Natalie K. Waran, and Robert J. Young. “The effect of a foraging device (a modified ‘Edinburgh Foodball’) on the behaviour of the stabled horse.” Applied Animal Behaviour Science 48, no. 1-2 (1996): 25-35.

56 Kiley-Worthington, Marthe. The behaviour of horses: in relation to management and training. JA Allen, 1997.

57 Willard, Judy G., J. C. Willard, S. A. Wolfram, and J. P. Baker. “Effect of diet on cecal pH and feeding behavior of horses.” Journal of animal science 45, no. 1 (1977): 87-93.

58 Broom, D. M., and M. J. Kennedy. “Stereotypies in horses: their relevance to welfare and causation.” Equine Veterinary Education 5 (1993): 151-151.; Marsden, M. D. “Feeding practices have greater effect than housing practices on the behaviour and welfare of the horse.” 1993. Proceedings of 8th International Symposium of Livestock and the Environment, University of Warwick, 6-9 July 1993.

59 Malpass, J. P., and B. J. Weigler. “A simple and effective environmental enrichment device for ponies in long-term indoor confinement.” Contemporary topics in laboratory animal science (1994).

60 Andrews, F.M., Nadeau, J.A., 1999. Clinical syndromes of gastric ulceration in foals and mature horses. Eq. Vet. J. Suppl. 29, 30–33.

61 Luescher, U. A., D. B. McKeown, and Helena Dean. “A cross‐sectional study on compulsive behaviour (stable vices) in horses.” Equine Veterinary Journal 30, no. S27 (1998): 14-18.

62 This is the Horsemen’s Pride Stall Snack Holder with Apple-Scented Jolly Ball for Horses, about $40 on Amazon. You’ll need to buy a snack to load in it separately ($10+); such snacks may last only a week.

63 “Behavioral Problems of Horses”, the Merck Veterinary Manual.

64 Houpt, Katherine A., and Sue M. McDonnell. “Equine stereotypies.” Comp Cont Educ Pract Vet 15 (1993): 1265-1271.


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