Call it what you want - cribbing, crib-biting or wind-sucking - we all know it when we see it or hear it. The horse latches onto a horizontal surface with his front teeth, arches his neck, and makes a grunting sound while pulling back. Afflicting an estimated 5 to 10% of horses, you're bound to see one sooner or later.
Cribbing is often grouped with other stereotypic behaviors, including weaving, stall walking, self-mutilation and wood chewing. However, many animal behaviorists now believe cribbing is more of a "functional" habit, meaning it meets a physiological need of the horse.
So what causes cribbing? Most people believe it's due to boredom or mimicry (picking up the habit from watching another horse do it). Wrong! Both have been ruled out by researchers as primary causes. Exceptions are rare. The more likely possible causes are management, ulcers and heredity.
it's unlikely that any two people maintain their horses in exactly the same manner, so it's difficult to isolate a single component that would trigger cribbing. However, researchers agree that feeding has a lot to do with it. Click here to read case histories about four different cribbers.
Common denominators are high-sugar "sweet" feeds composing a large portion of the horse's diet, limited roughage, and long periods with no available feed.
When cribbers are fed a "sweetened feed" (pellets are usually bound together with molasses), they crib 30% of the day vs. 16% of the day when fed plain oats as their grain concentrate. Sweets, even apples and carrots, trigger cribbing so reliably they're used to test drug efficacy for cribbing reduction.
The lack of forage also has an impact on the frequency of cribbing. Research in the United Kingdom demonstrated feeding grain caused the study horses to increase their cribbing behavior from a baseline of 11 cribbings in 5 minutes to 24 cribbings in 5 minutes and the duration of this elevation was 40 minutes. After being fed forage, cribbing fell to 5 attempts in 5 minutes and the decrease lasted for 50 minutes.
Foals fed a concentrate after weaning are four times more likely to become cribbers than foals fed forage only. So, if you want the recipe to produce a cribber, it's: early weaning, a high concentrate/low forage diet, infrequent feedings, social isolation and a stall environment.
ULCERS. Since the advent of endoscopy for horses, the link between ulcers and cribbing has strengthened, but no one will state unequivocally that one causes the other. Many horses with ulcers don't crib, and some cribbers don't have ulcers.
We know foals who crib have more serious stomach ulceration than foals that don't. We also know that cribbing stimulates the vagus nerve, which increases stomach pH. And we know a cribber?s motivation to crib is equal to his motivation to eat.
There is a widely held apocryphal belief that cribbing releases saliva that then buffers stomach acid. One small study (two horses with cannulated parotid glands) demonstrated the opposite: After 20 cribbing efforts, only 1 ml (5 ml = 1 tsp.) of saliva was produced; by comparison, 31 ml of saliva was produced while consuming 200 grams of grain. It has been found, however, that cribbers have a lower baseline level of saliva than non-cribbers.
Administering antacids to cribbers does raise the pH of the stomach (making it less acidic), but it doesn't reduce the frequency of cribbing. According to a spokesperson at Merial, the company that makes the ulcer medicine GastroGard, no studies have been done to determine the efficacy of their product on reducing cribbing.
Cribbing may be the horse's attempt to release saliva - particularly in the absence of roughage - but the amount of time spent cribbing can interfere with roughage intake when it is available, causing increased ulceration and weight loss.
HEREDITY. There seems to be little doubt among researchers that cribbing has a heritable component. Among breeds, Thoroughbreds hold the distinction of having the largest population of cribbers (8.3 to 10%). However, don't blame racing. Standardbreds, which undergo similar training, feeding and housing regimen, have a much lower incidence.
Several studies have confirmed a high incidence of cribbing in dressage horses. This discipline includes many warmbloods, who, by definition, trace back to Thoroughbreds. School, pleasure and endurance horses have the lowest reported pools of cribbers.
No one has yet documented the method of inheritance. It does appear to be somewhat genetic, and we know it skips generations. Nevertheless, we can't state strongly enough that cribbers should never be bred, regardless of their conformation or potential.
BOTTOM LINE. If you have a cribber, make every effort to keep forage or pasture available at all times, using slow feeders. Toss out all the sweet feeds and treats. Check for ulcers, and maximize turnout on quality pasture with good buddies.
See our anti-cribbing collar product recommendations by clicking here.
Cribbing is still a controversial topic, as there truly is no one correct answer. That said, experts agree that whether you use a collar or choose not to, you still owe it to your horse to make those critical management changes.
Article by Contributing Writer Beth Benard