Put yourself in your horse's shoes for a day. Is his life full? Does he have the important three Fs vital for herd animals - friends, forage and freedom? If the answer is no, chances are he will be exhibiting some sort of stereotypic behaviour, or be liable to do so unless his situation improves.
Stereotypic behaviour is defined as "a behaviour that is repeated but has no apparent purpose or function".
It includes things such as cribbing, weaving, box or fence walking, kicking and biting (himself). All rather annoying at best, and disturbing or even dangerous at worst.
Stereotypic behaviour in horses has been exhaustively studied and researched, and one of the main causes seems to come down to stress brought on by poor management. The difficulty is that since the stereotypic behaviour triggers the release of endorphins, which make the horse feel good, it is a habit that once ingrained becomes hard to cure - much like humans biting their fingernails.
Coping with horses' stress and boredom
Experts now largely agree that stereotypy is the way horses cope with stress and ease frustration and boredom. Some believe there may also be a genetic disposition to stereotypy inherent in certain horses.
Horses in all sorts of situations can demonstrate stereotypy - even those kept turned out with plenty of companionship - but the vast majority of cases occur in horses kept stabled for long periods.
If your horse is displaying stereotypic behaviour already it may be difficult to stop it, but there are ways to limit it. Prevention is better than cure, obviously, so it's wise to keep your horse's stress to a minimum.
What is required is for us to manage our horses in a way that is as close to nature intended as possible. Not easily done with our domesticated steeds, especially if they are energetic equine athletes that we expect to be lively and perform perfectly at our convenience, but stay quiet and well-behaved when it suits us.
Horses sleep very little - between five and seven hours a day - and spend the rest of the time alert. Nature has designed them to fill their time grazing, moving around, socialising, playing, and cantering for the pure joy of it. With us humans controlling their activity - putting restrictions on much of this natural behaviour - stress can result and stereotypy could well be the consequence.
Most horses cope well with the demands we place on them, but about 25% (according to one study) will have problems and develop stereotypic behaviour.
Stereotypy Triggers
Long periods of stable confinement seems to be the most common trigger of stereotypy, but there are other factors that could cause it such as the stress induced by early weaning, training practices, feeding and a change in environment.
One thing horse owners can guard against relatively easily is to avoid leaving a horse alone and bored in a stable for most of the day. At times there may be no option, if a horse needs enforced stall rest or is under quarantine, for example. In such cases you can ensure his environment is enriched so as to be as stimulating as possible.
Horses need to play and let off their energy. Stable toys such as horse balls, hanging toys and licks act as a diversion to confined horses, but make sure you change them around frequently to add interest.
Being herd animals, companionship is all important to horses, so stable design for confined horses should allow for this. Ideally a stabled horse should be able to see other horses over the stable door, or through dividing grills. He'll also enjoy watching what's going on in the yard outside, or the aisle. Even his own reflection in a (safety) mirror will bring him comfort. If he doesn't have the company of other horses make sure he's at least got plenty of frequent human attention and interaction.
Several researchers believe that cribbing and other oral stereotypies is related to hunger. If the horse's appetite is not satisfied, he will make eating motions, which can become a habit (particularly with younger horses) associated with anticipating his regular meal times, or seeing other horses eat. The solution to this is making sure the horse's feeding is as close as possible to natural grazing behaviour - which means allowing him to eat almost constantly! Increased amounts of hay fed frequently, or more regular turnout to allow for grazing, should reduce instances of cribbing.
Once cribbing has become an ingrained habit, it is far more difficult to stop. There are various products on the market designed to "cure" cribbers. These include devices such as the Weaver Miracle Cribbing Collar, recommended because it doesn't impair the horse's ability to eat, drink and breathe normally. You can also use one of a variety of products to coat the surfaces on which the horse is inclined to crib, which have an unpleasant taste designed to deter the horse from chewing.
It all comes down to this: you can prevent stereotypies by keeping your horse happy and stress free by meeting his needs. If you notice a stereotypy developing, treat it as an alert to the fact that you are doing something wrong - make an effort to find out what that is, and correct it.