Cribbing, also known as crib-biting, is the most common oral stereotypic behaviour seen in horses. Cribbing involves the horse repeatedly and compulsively grasping an object between its teeth and sucking in air.

Horses may crib bite for many hours per day, reducing time for other important activities such as eating and socializing. Cribbing can also contribute to poor body condition, dental problems, and increased risk of gastric ulcers or colic.

This behaviour often begins as a coping mechanism. Addressing possible stressors such as lack of access to forage, confinement, boredom, and social isolation can help to prevent cribbing.

Identifying and treating underlying health conditions such as gastric ulcers can also improve comfort and promote calm behaviour.

Half of all cribbing cases are believed to start in the first 5 months of life when foals are typically weaned. Allowing a gradual weaning process may reduce the risk.

Your horse’s feeding program can influence the expression of stereotypical behaviours. If your horse is cribbing, submit their diet online for a free evaluation by our equine nutritionists.

What is Cribbing?

Cribbing is an example of an oral stereotypy. It involves the horse grasping onto a fixed object with its teeth, biting down, and gulping air into the cranial esophagus through the contraction of the neck muscles.

Cribbing causes a characteristic grunting noise as air is sucked into the esophagus. Contrary to what some believe, the air is not swallowed which makes cribbing distinct from aerophagia.

Horses can crib on any solid object at around chest level, such as a fence board, stall door, or bucket. Cribbing does not involve chewing the object but can cause damage to the environment as the incisor teeth clamp down. Tooth erosion can also occur.

Horses that display cribbing behaviour are highly motivated to perform the stereotype. They can crib-bite for up to 5 hours per day, with some reportedly spending up to 65% of their time on this activity. It is considered a post-prandial stereotypy because it occurs most frequently after a meal. [2]

Cribbing is not seen in wild horses but has been observed in domesticated horses dating back to 1578. [18] This suggests that the behavior is related to modern management and feeding practices, although a genetic component may also play a role. [20]

Stereotypical Behaviors

A stereotypical behavior is a repetitive behavioral sequence with no obvious goal or function. The behaviors are believed to be automated coping responses or expressions of frustration.

Other examples of stereotypic behaviors include:

  • Box-walking
  • Wind sucking
  • Wood chewing
  • Weaving

Up to 32% of the horse population is thought to display stereotypical behaviour. Crib-biting affects 8.3% of horses. [1]

Wind sucking is a related behaviour that may occur if there are no surfaces available for a horse to grasp with its teeth or if the biting behaviour is punished.

Wind sucking involves the same contraction of neck muscles and the sucking of air without clamping down on an object with the teeth.

Why Does my Horse Crib Bite?

Stereotypical behaviours may be an indicator of poor welfare, either in the past or present. They are coping mechanisms designed to reduce stress and provide control over an environment.

It is thought that the majority of equine stereotypical behaviours are established in young foals, typically within one month of weaning. [1][3][4]

Stereotypies like cribbing may develop for the following reasons: [4] [5]

  • Being unable to perform a behavioral pattern the horse is motivated to perform. For example, horses on a forage-restricted diet are not able to perform species-appropriate feeding behaviours.
  • Being unable to avoid a fearful or stressful situation. For example, some stereotypies develop in response to negatively reinforced training.
  • Being kept in social isolation or long periods of confinement. For example, stereotypies are more common in individually stalled horses.

Physiology of Crib-Biting

Crib-biting and other stereotypical behaviours cause dopamine to be released in the brain. The temporary spike in dopamine helps horses cope with stress.

Dopamine is a neurotransmitter thought of as the “pleasure” chemical. It plays a major role in the reward centre of the brain. [5]

Chronic stress triggers the release of beta-endorphins, stimulating secretions of dopamine in an area of the brain known as the striatum.

This activates dopamine receptors in the basal ganglia, which is the part of the brain where stereotypies are thought to develop. [6]

In crib-biting horses, there are more D1 and D2 dopamine receptors within an area of the brain known as the nucleus accumbens. There are also fewer D1 and D2 receptors in the caudate nucleus, a key area for action-outcome learning.

This suggests that cribbing horses are prone to habit formation and are highly motivated to carry out repetitive actions. Horses affected by stereotypical behaviours may also have a reduced capacity to learn and train. [7]

Causal Factors

Chronic stress is thought to contribute to stereotypical behaviours, including cribbing. Other risk factors have been identified including: [7]

  • Personality
  • Breed; Thoroughbreds and warmbloods are up to 3 times more at risk
  • Genetics
  • Nutrition
  • Stable management; stabled horses are more at risk
  • Weaning experience
  • Type of work
  • Time of initial training
  • Sex; male horses, particularly stallions, are more at risk than mares

Weaning

Domestic weaning in horses typically occurs at around 4-6 months. In contrast, weaning occurs at 8-9 months in feral horses or domesticated horses allowed to wean naturally. [9]

Researchers suggest that oral stereotypies, including crib-biting, may develop due to premature cessation of nursing behaviour. General weaning stress and abrupt dietary changes may also play a role. [11]

Research also shows there is a four-fold increase in cribbing among foals fed concentrates post-weaning, rather than grass or forage. [12][13]

Ensuring your foal has adequate access to grass or forage may reduce the risk of cribbing during this dietary transition. You can also ease stress and digestive issues associated with weaning by offering new feeds while the foal is still suckling.

In addition, gradual group weaning significantly reduces weaning-associated stress and related behaviours such as vocalization, locomotion, cribbing. [8]

The good news is that most stereotypical behaviours can be curtailed within the first 12 weeks of their development, as long as appropriate management practices are applied to remove the causal stressor. [3][9][10]

Social Isolation

Horses are herd animals with a strong desire for social interaction. Stabling or turnout with another horse significantly reduces stereotypic behaviors such as cribbing.

One study found that 22% of young horses stabled individually developed crib-biting, whereas no horse in the pair housed group did. [16]

Isolated housing at a young age is also associated with other abnormal behaviours, including weaving and boxwalking, which did not occur in pair housed horses. In total, 67% of horses that were individually stabled showed stereotypical behaviours. [16]

Socialization is important for horses, but the wrong social grouping can also cause problems. Horses that are low in the social hierarchy are more likely to experience stress and to have less access to resources including shared feed and water.

Boredom

Boredom is commonly cited as a reason that horses crib. Horses kept in stalls with limited access to turnout may lack sufficient engagement to support optimal psychological well-being.

If your horse currently spends long periods of time idle, they may benefit from enrichment activities or toys to make their environment more stimulating.

In one study, providing horses with an oral stall toy slightly decreased cribbing rates. [23]

Genetics

Genetics appear to play a role in the development of this behaviour, since 8% of Thoroughbreds crib followed by high rates of Quarter Horses and other warmbloods. [4]

Researchers have also found that cribbing is highly heritable, meaning that horses frequently pass on this trait to their offspring when they breed. [20]

However, researchers do not yet know which genes are risk factors for crib-biting. [20]

Copying Behaviour

It was previously thought that horses mimic the expression of stereotypies or “stall vices”. However, this has been disproven.

Survey data from horse owners reported that only 1% of horses began cribbing after coming into contact with a horse that displayed this behaviour. [21]

Horses do not copy stereotypical behaviours when stabled near other horses. Instead, behaviours arise from shared exposure to stress-inducing farm management techniques. [4]

Nutritional Factors

Several feeding practices are associated with cribbing in horses. Horses have an innate drive to forage and are best served by a diet that consists primarily of pasture or hay.

Modern feeding practices, such as high-grain diets and intermittent access to feed, prevent foraging behaviours and contribute to behavioural issues. [4]

Intermittent Feeding

Horses are trickle feeders that evolved to graze near-continuously throughout the day. Feral horses and domesticated horses allowed to free graze will forage for up to 16 hours per day. [17]

Domesticated horses are often stabled and fed two large meals per day. This style of intermittent feeding leads to long periods without forage during which the horse has nothing to chew or graze on. Research shows this may cause horses to crib-bite.

Grain-Based Feeds

Research also shows a higher incidence of crib-biting in horses fed more concentrate feeds and less forage. [11] The type of grain that is fed during meals also plays a role. Horses fed 1 kg of sweet feed containing 20% molasses spent more time cribbing after the meal than horses fed oats. [23]

This may be due to the high sugar content of the sweet feed. Eating a diet high in sugar and starch increases the risk of digestive issues linked to cribbing, including ulcers and hindgut acidosis.

High NSC grain-based feeds should be eliminated from your horse’s diet and replaced with long-fibre roughage, as much as possible. This will meet your horse’s inherent drive to forage and decrease the risk of digestive complications.

Gastric Ulcers

Gastric ulcers are painful lesions that occur in the stomach lining of the horses. Ulcers can lead to behavioural changes, including increased aggression, reluctance to exercise, girthiness and picky eating.

Crib-biting is strongly associated with gastric ulcers. [25] Foals that develop crib-biting after weaning typically have higher rates of stomach ulceration, which increases their sensitivity to dietary changes.

One study found that 60% of crib-biting weaned foals had gastric ulcers, whereas ulcers were only present in 20% of weaned non-cribbing foals. [9][11]

It has long been believed that horses with ulcers may crib-bite to increase saliva flow to the stomach. Saliva buffers gastric acid secretions and may help relieve pain associated with ulcers. [7]

However, some studies suggest that crib-biting does not increase saliva production. Instead, cribbing may actually increase the risk of ulcers by stimulating gastric secretions. [2]

Horses that are cribbing should be monitored closely for common warning signs of gastric ulcers and treated accordingly. If your horse has ulcers, add Visceral+ to your feeding program to promote gut health and support natural intestinal barrier function.

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Nutrient Deficits

Wood chewing is another undesirable behaviour that often coincides with or precedes crib-biting. This stereotypy is also related to low-forage diets and intermittent feeding. [4][6]

Wood chewing is sometimes a sign of nutritional deficits. Horses may chew on wood or lick dirt if their diet is not providing adequate amounts of vitamins and minerals. [24]

For example, horses have a strong drive to consume salt, but equine diets are commonly low in sodium. This can lead to pica, which is the desire to consume non-edible substances including bones, soil, hair, bedding, and feces.

Low sodium is of the simplest nutritional deficits to correct for by adding plain salt directly to your horse’s feed and providing loose free-choice salt at all times. Most horses require 1 – 2 tablespoons (15 – 30 grams) of salt per day to meet their sodium requirements.

If your horse performs crib-biting, wood chewing or dirt licking, consult with qualified equine nutritionist to have your horse’s diet evaluated. A nutritionist can help you identify and address vitamin and mineral imablances.

How to Feed Cribbing Horses

All horses should have near-constant access to forage, whether hay or pasture.

This requires choosing hay that matches your horse’s requirements to allow for maximal foraging behaviours without oversupplying energy and protein.

If your horse has high caloric needs to support their exercise level, consider replacing some or all of the grain content of the diet with oil such as flax or w-3 oil. Oils and high-fat feeds provide energy without compromising digestive health.

Highly digestible fibre sources such as beet pulp or soy hulls are also suitable calorie sources that support digestive health.

Ensuring your horse’s diet is well-balanced to meet their vitamin and mineral requirements may also help decrease behaviours such as crib-biting and wood chewing. Mad Barn’s Omneity is a concentrated vitamin/mineral supplement that does not contain any grain fillers.

If you suspect gastric ulcers and digestive discomfort are contributing to crib-biting, consider adding a digestive health supplement such as Visceral+ to support repair processes and provide nutrients for the digestive tract.

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4 stars
5%
3 stars
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3%
1 star
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  • Clinically proven for ulcers
  • Restore integrity to gut lining
  • Prevent stomach upset recurrence
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Why is Cribbing Bad for Horses?

Cribbing is a nuisance for stable owners because it can lead to damage in the environment and potential injury for the horse.

Cribbing is also associated with various health concerns, including: [4][14][15]

  • Excessive dental wear and damage to incisors from biting down on fixed hard objects to gulp air.
  • Poor body condition score with less time spent feeding and grazing as well as increased calorie expenditure.
  • Higher risk of colic, specifically from epiploic foramen entrapment.
  • Poor mental state where the cause of cribbing has not been addressed or the horse is in an actively stressed state.
  • Increased risk of gastric ulcers, equine motor neuron disease and temporohyoid osteoarthropathy. [22]

How to Stop your Horse from Cribbing

There are management practices you can adopt to help reduce your horse’s frequency of cribbing. Ensure your horse’s environment is conducive to supporting their welfare, including:

  • Constant access to forage and water
  • Plenty of turn out with other horses
  • Minimize concentrate feeds as much as possible
  • Feed oil for weight gain or added energy, instead of starch
  • Allow for natural weaning in a group and provide a gradual transition to hay or grass pasture
  • Provide stable toys or enrichment activities

Anti-Cribbing Devices

In addition to management practices, anti-cribbing devices, medications and veterinary procedures might be required if your horse is suffering serious health consequences:

  • Crib straps, collars, rings or muzzles help to prevent biting down on objects
  • Pharmacological agents may reduce cribbing, but only for short periods of time
  • Anti-cribbing sprays applied to fixed objects in the environment
  • Surgical procedures; in rare cases, a neurectomy and myectomy cuts nerves and muscles so the horse physically cannot crib

For some horses, cribbing is a permanent habit that is hard to stop once the behaviour is established. In certain cases, trying to stop your horse from crib-biting can do more harm than good.

Particularly if your horse’s welfare is otherwise good, preventing your horse from cribbing may only increase stress levels and take away a coping mechanism. [7]

How to Prevent Crib-Biting?

It is easier to prevent a horse from developing this stereotypic behaviour than it is to stop cribbing once it has been established.

Fortunately, the same feeding and management practices that help to prevent stereotypies also support the optimal welfare of your horse. Meeting your horse’s species-appropriate nutrition, socialization, weaning, and housing needs will naturally lead to a lower risk of crib-biting.

Recommended practices include the following: [2][4][6][7]

  • Allow natural weaning by the mare when the foal is 8-9 months.
  • Weaned foals should be kept with other horses of the same age and should be housed in pairs if they must be stabled.
  • Weaned foals should be kept on grass pasture as much as possible and should be fed a fat- and fiber-rich diet rather than grain-based concentrates. Avoid high sugar and starch feeds.
  • Ensure your horse has near-constant access to forage to avoid long periods with an empty stomach. Intermittent feeding increases the risk of ulcers.
  • Provide your horse with constant access to fresh water and free choice loose salt. Feeding salt encourage thirst and promotes hydration. Consumption of water helps buffer stomach acids and prevents ulcers.
  • Minimize the feeding of high-NSC feeds. If your horse needs to gain weight, use fat sources for energy rather than starches.
  • Reduce your horse’s exposure to common stressors. If your horse’s behaviour changes, try to determine and remedy the underlying factors.
  • Ensure your horse has plenty of socialization and enrichment. Stabled horses should be allowed to see and/or touch other horses if not stabled in pairs.
  • Take steps to reduce the incidence of gastric ulcers and be vigilant for early signs of ulceration. Feed a gut health supplement, such as Visceral+, if your horse is at high risk of ulcers.

Summary

Cribbing is a common equine stereotypic behaviour that is correlated with early weaning, stress, isolation, low-forage diets, and idleness.

It is believed to be a coping mechanism for chronic stress and frustration, potentially related to poor welfare or domestic stabling practices.

Boredom, feeding plan, socialization, and underlying health issues such as gastric ulcers can be addressed to help reduce cribbing frequency.

If your horse has a cribbing habit, submit their information online for free suggestions from our equine nutritionists on how to help reduce this behaviour through feeding and management.

Although cribbing is associated with some health concerns, as long as all current welfare issues are addressed, the cribbing horse can lead a full and happy life.

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References

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