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.
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.
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.