For a natural solution to prevent cribbing, there are products available to feed your horse.
Things to Consider:
Feeds -- To use in conjunction with sprays and solutions, or by itself, there are specialty formulated feeds that can help stop chewing.
Boredom -- Oftentimes, cribbing can stem from boredom. If a horse is given feed or other food to eat, this can keep them out of trouble.
Catch it early -- Cribbing can be a hard habit to break your horse of. Watch for signs early and began treatments and preventatives as soon as possible.