I’d like to talk about a distinct behavior seen in some horses called cribbing. Many horse people have heard of it even if they’ve never seen it themselves. Cribbers are horses that exhibit a particular stable vice, also called a stereotypic behavior. Such a behavior is defined as repetitive and has no obvious function; it can be classified as a compulsive behavior.
Cribbing is a specific type of stable vice where the horse presses down with his incisors on a firm surface, such as a fence post, stall door, or gate. With the incisors on this surface, the horse will press down and back, arching his neck and gulping in air, and making a distinct belching noise. This behavior is not only destructive to barns and fences, but also causes excessive wear on the horse’s incisors. Cribbing may also be linked to gastric ulcers and certain types of colic, but this has not been conclusively proven in studies.
So, why would a horse exhibit such bizarre behavior? Veterinary behaviorists agree that the main root cause of such stereotypic behavior is lack of appropriate physical, mental, and social stimulation. Chiefly, this comes down to how we house our horses.
Thinking back to the way horses evolved as a prey species, combined with the fact that mustangs, feral horses, and horses housed in a “natural” manner do not exhibit such behaviors, it’s not surprising that a common way horses are kept, namely in a stall and fed distinct meals of high concentrate carbohydrates, leads to innate stressors on the horse’s psyche, resulting in behavioral problems. Horses are meant to graze upwards of sixteen hours a day, walking along pastures and, as herd animals, socializing with others of their species. Take away these natural elements and you are asking for trouble.
Curing a cribbing horse is often unsuccessful. This compulsive behavior is so entrenched that even putting a cribbing horse out on pasture 24/7 usually does not rid him of this action. Frustratingly, cribbers are very good at finding something to crib on. There are cribbing “collars” on the market that attach around the horse’s throat. These collars prevent the horse from tensing his neck muscles when gulping for air during cribbing behavior. This physical deterrent sometimes helps, but there are some horses that crib despite the collar. For this reason, some boarding stables are unwilling to house a horse that is known to crib.
By far, prevention of such behaviors is worth way more than any “cure.” Raising horses so that they have access to pasture, herd interaction, and plenty of roughage is key to preventing compulsive behaviors. If pasture use and herd interaction are limited, providing ample hay to allow for a simulated grazing schedule will help. Although grain is needed for growing horses and those with intensive training schedules such as racehorses or other competitive athletes, most other adult horses don’t need the “hot” energy such diets provide. In the end, the closer to nature we can keep our horses, the healthier they are.
Dr. Anna O’Brien