A cribbing horse grasps a surface with his incisors, flexes his neck, and swallows air. As the air passes through his throat, it makes a gasping, grunting, or groaning sound.
The behavior can be hazardous to the horse's health, and there is no "cure" for the condition. Once a horse starts to crib, he might feel the need to latch onto any surface in his reach. Most often, horses will crib on fence boards, stall doors, and feed tubs.
Auburn University professor and extension horse specialist Cindy McCall has even had reports of horses cribbing on crossties in a barn aisle and — one particularly determined cribber — on his own shoulder.
There are ways to manage a horse's cribbing, and research is underway to better understand and work with cribbers. Here's a closer look.
What kicks off a horse's cribbing behavior may be fairly complex. "There are a range of risk factors that come together, so personality, breed, diet, early experience — including weaning method — all have a role to play," says Dr. Daniel Mills, a well-known equine behaviorist who's researching stereotypes at the Royal College of Veterinary Surgeons in the United Kingdom.
Here's a rundown of possible causes.
Breed. A primary factor in determining whether a horse will crib is the breed. Thoroughbreds are the No. 1 breed for cribbing, with 8 percent of them exhibiting the behavior. Quarter Horses are next most likely. Evidence points to a genetic link for cribbing.
Weaning/feed. "Cribbing usually at weaning or when you change the horse's diet," says Dr. Katherine Houpt, a professor of behavioral medicine at the Cornell University College of Veterinary Medicine. "When you bring him off of pasture, stick him in a stall, and give him sweet feed—that continues to be the main stimulus." The role that sweet feed plays in triggering cribbing is still unknown. However, feeding straight oats seems to decrease the frequency of cribbing in horses exhibiting the behavior.
Dr. Mills believes half of all cribbing horses start within 20 weeks of age, the typical weaning period. Weaning horses using careful management can reduce their likelihood of becoming cribbers: "Ensuring good turnout, gradual weaning, and minimizing the use of concentrates, especially early in life" can aid in prevention, says Dr. Mills.
Anxiety. Some horses are naturally more anxious and stress-prone, and Dr. Mills says that could be a predisposition for cribbing. In fact, the behavior is least often found in cold-blooded horses, such as ponies and draft breeds, which tend to have less-worrisome personalities.
Stomach upset/ulcer. Dr. Mills has treated cribbing horses with antacids and found this might significantly reduce the behavior. His team's research is ongoing.
Christine Nichol of the Centre for Behavioral Biology at the University of Bristol in the United Kingdom has found an association between gastric ulcers and cribbing.
McCall says that she and her team haven't reached a conclusion as to whether cribbing causes stomach issues or whether the presence of stomach issues is the impetus for cribbing.
Colic. Cribbing horses can damage equipment and facilities with their grasping and pulling behavior. The real dangers, however, are
the dangers that the horse poses to himself. "Cribbing does present a big risk factor for colic," said Dr. Houpt. She hasn't found a direct correlation between the frequency of cribbing and the risk of colic, although she's lost one-third of the cribbing horses she's studied due to colic.
Tooth damage. Cribbers wear down their front teeth. They'll crib on any solid surface, very often including metal surfaces.
Eating disorders. Many cribbers appear thin. "Our skinny ones are skinny because they'll crib at the expense of eating," says McCall.
Cribbing is learned. The belief that horses learn to crib from other cribbers is untrue, says Dr. Houpt. Research shows only 10 percent of cribbers pick up the habit from others, and those horses were probably genetically predisposed.
Cribbing horses are bored. The idea that horses crib because they're bored may also be untrue. Dr. Houpt has found that enriching their environment and providing regular exercise isn't a help. Other experts disagree, saying cribbing horses that receive regular exercise and other types of environmental stimulation, such as mirrors and toys, are less likely to crib.
Horses crib to get "high." Research into endorphin levels — the "feel good" chemicals in the bloodstream — hasn't yielded consistent results as to whether cribbing horses actually get a "high" from their actions. One possibility, Dr. Houpt suggests, is horses might not crib because of the endorphins; rather, the endorphins that are already present from another source — such as a type of feed — might be a cause for the action.
7 Management Techniques
Some experts think the dangers posed to the cribbing horse require management. Others say cribbing should be reduced using a cribbing collar, but the control should be removed for short periods of time so a horse can occasionally act on his need to crib without incurring too much physical damage.
"I would generally say, unless the horse colics recurrently, that it's better to allow him to crib than to prevent it through collars or surgery," says Dr. Mills. "These interventions do nothing for the motivation."
Here's a look at seven common cribbing-management techniques.
Forage. Horses kept on pasture and those with free-choice access to hay may crib less.
Antacids. As mentioned, research has shown that some cribbing is related to ulcers. Providing an antacid in your horse's diet could be beneficial.
Cribbing collars. Dr. Houpt says these popular neck collars do seem to work, but "you have to make it so tight that often the horse develops lesions." Fitted around the horse's jowl at the throatlatch, a cribbing collar doesn't affect a horse's breathing, eating, or drinking when he isn't attempting to crib. When the horse does attempt to crib, the collar applies pressure to the throatlatch so he can't arch his neck and suck in air. Note: Avoid shock collars, which are often viewed as cruel.
Cribbing muzzles. Muzzles do work, although horses will try their hardest to remove them. A metal and nylon muzzle clips to the horse's halter and allows the horse to graze and drink, but the horse can't get his mouth around a solid object to crib.
Cribbing rings. "They are copper hog rings that you put around the horse's teeth so they can't make contact with the fence," says Dr. Houpt, who has used these in her research. "It works, but they don't stay in very long, and it does slow down their grazing."
Premises paint. Several wood coatings are produced with the intention of preventing cribbing. Some people swear by hot pepper sauce. But such treatments have mixed results.
Modified Forssell's procedure. A surgery designed to prevent cribbing is the modified Forssell's procedure. A surgeon cuts muscles and nerves in the horse's neck, and removes some muscle tissue. This makes it difficult for the horse to arch his neck and suck in air.