Cribbing in Horses

Why Horses Crib and What You Can Do

By: Dr. Lydia Gray

Why Do Horses Crib?
Supplements That May Lend Support
Possible Diagnostic Tests
Prescription Medications Available

Other Management Suggestions
Additional Resources

Why Do Horses Crib?

Cribbing is one of several “stereotypies” or seemingly functionless, repetitive behaviors that also include weaving, stall-walking, pawing and head bobbing. A behavior that is often confused with cribbing is woodchewing, in which a horse chews wood objects in its environment such as trees and fences. Woodchewing appears to be a normal behavior in horses that are simply seeking more long-stem forage or “chew time.” Recently, behavioral experts have suggested that cribbing also serves a purpose, that of allowing predisposed horses to cope with stress through an action that produces a calming or soothing effect.

Cribbing (also known as “wind-sucking”) refers to when a horse grasps an object with its upper front teeth, pulls back, arches its neck, and appears to draw air into its esophagus while making a characteristic grunt. Although it has been shown that horses do not actually “swallow air” during cribbing, negative pressure is generated which may explain why there is an association between cribbing and a specific type of colic called epiploic foramen entrapment. Other reasons many owners desire to discourage cribbing are that it can lead to poor performance, weight loss, flatulence, and abnormal tooth wear, as well as destroy property.

Although many horse owners believe that horses learn to crib by watching other horses perform the behavior, this has not been documented. What has been discovered is that certain lines or pedigrees of horses seem to possess the “cribbing gene” which is expressed when the environment becomes stressful. Therefore, experts believe it is more likely that the offspring of a cribber will take up the behavior than a horse with no cribbers in the family tree.

Cribbing Solutions

Supplements that May Lend Support

Though the true cause (or causes) of cribbing have yet to be identified, one theory suggests cribbing may be associated with stomach discomfort. If so, then products that soothe the lining or neutralize excess acid may have an effect. Another theory is that the community of microorganisms in the digestive tract, or the “microbiome,” is distressed, so ingredients to support a comfortable and properly functioning hindgut (ie cecum and colon) may be helpful. Finally, because there may be an emotional component to cribbing, that is, the horse is trying to cope with stress in the environment, some report success with products from the calming supplement category.

Possible Diagnostic Tests

It is important to try and find out why a horse cribs and treat that specific problem or remove that cause of stress if possible. A veterinarian can determine if an unhealthy stomach or GI tract are factors leading to cribbing and recommend treatment. An investigation into how and where a horse is kept -- as well as how and what he is fed – may yield clues as to why a horse cribs. For example, a horse kept in a stall and fed hay and grain twice a day may be more likely to crib than a horse maintained on pasture with several other horses or provided forage round-the-clock.

Prescription Medications Available

There are no specific drugs to treat cribbing. However, a study testing the ability of dextromethorphan to reduce the behavior was successful in 8 of 9 horses with cribbing being completely suppressed in approximately half the horses for a period of time. Dextromethorphan is thought to work by blocking dopamine receptors in the brain, thereby preventing the endorphin release (the “reward”) that usually accompanies cribbing behavior. This means that the act of cribbing did not calm or soothe the horse and so the horse stopped doing it.

Other Management Suggestions

Experts generally agree it is better to prevent cribbing in the first place than try to eliminate the behavior once it is established. Therefore, owners should try to avoid situations that are known to increase the risk of cribbing such as stressful weaning combined with overfeeding grain, a high grain diet in general, lack of access to forage, and little turnout or ability to socialize with other horses. Substituting a ration balancer or multi-vitamin/mineral supplement for grain, using a small-hole hay net, and stalling as little as possible are advised.

If a horse must be stalled, then a special cribbing “bar” can be constructed to allow the horse to relieve his stress without causing damage to himself or the barn. If necessary, cribbing collars reduce a horse’s physical ability to crib, but because they limit the horse’s own coping mechanisms against stress, the behavior is often worse when the cribbing collar is removed. As a last resort, surgery is an option if the cribbing behavior is a serious threat to the horse’s health.

Cribbing in Horses

Why Horses Crib and What You Can Do

Why Do Horses Crib?

Cribbing Solutions

Supplements that May Lend Support

Possible Diagnostic Tests

Prescription Medications Available

Other Management Suggestions

Additional Resources

Further Reading for You

From our Ask the Vet Blog:

From our Ask the Vet video series:

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