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Stable vices are stereotypies of equines, especially horses. They often develop as a result of being confined in a stable with insufficient exercise, boredom, hunger, excess energy or isolation. They present a management issue, not only leading to facility damage from chewing, kicking, and repetitive motion, but also lead to health consequences for the animal if not addressed. They also raise animal welfare concerns.
Stereotypical behaviors in animals are generally thought to be caused by artificial environments that do not allow animals to satisfy their normal behavioral needs. Rather than refer to these behaviors as abnormal, it has been suggested that they be described as "behavior indicative of an abnormal environment."
It was once thought that stable vices may be learned by observing other horses already performing the behaviors, but studies on the topic to date have failed to establish this as a cause. Stereotypies are correlated with altered behavioral response selection in the basal ganglia. Although a more enriched environment may help minimize or eliminate some stereotypical behavior, once established, it is sometimes impossible to eliminate them due to alterations in the brain.
Common stable vices include:
- Wood chewing (lignophagia): Gnawing on wood out of hunger or boredom. This can develop into the more serious vice, Cribbing.
- Cribbing: When the equine grabs a board or other surface with its teeth, arches its neck, and sucks in air. This can harm the teeth and may lead to colic. Cribbing can be caused either by nervousness or boredom, it may release endorphins in the horse. Recent research suggests that cribbing increases salivation and may reduce stomach discomfort.
- Weaving: Rocking back and forth in a repetitive fashion, possibly a self-stimulating behavior. Weaving is often seen with particularly nervous animals, or those that do not get out of their stalls often enough. Problems with weaving can include weight loss and uneven hoof wear, unnatural stress on the legs and lameness.
- Wall kicking: Kicking the walls of its stall with hind legs. This raises the potential of damage both to the equine and to the barn. Usually this is caused by a lack of exercise and boredom. Wall-kicking is one habit that is often acquired by others in the barn once an individual starts doing it.
- Biting: A nervous or anxious equine may reach out of its stall to bite at passers-by, human or animal. Box stall designs that keep the horse from reaching its head out prevent harm to other animals, but some horses may attempt to bite a handler when the person enters the stall.
- Bolting feed: Eating food too fast without adequate chewing, this potentially can lead to certain problems in the digestive system including choke and colic.
- Circling: Like weaving, this is a repetitive movement, only the individual circles compulsively in its stall. This habit can also lead to weight loss and lameness.
- Pawing or digging: The equine may paw with its front feet. This can lead to abnormal hoof wear and lameness, and may also damage the flooring of the box stall. An equine that paws can dig a noticeable hole in a dirt-floored barn in a very short time.
- Masturbation: A male horse, either a stallion or a gelding, will use his abdominal muscles to rhythmically bounce his penis against his belly. Previously believed to be a vice caused by boredom, confinement, or discomfort masturbation by stallions and geldings is now understood to be a normal behavior. Furthermore, this behavior rarely results in ejaculation and does not impact fertility.
Other behaviors that arise from boredom or frustration may not be vices with health or safety consequences, but still present management challenges and there is little that can be done to stop them. These include destruction of buckets, mangers, and feed tubs; defecation in the manger or water bucket; dumping water buckets; sloshing feed in water and then scattering it on the ground, and so on.
In most cases, reducing confinement and providing the animal a more natural setting reduces the incidence of stable vices.
There are stopgap "cures" that can be provided in the stall to keep a horse busy or out of trouble, including increased exercise, feeding of larger quantities of lower-quality food (so the animal spends more time eating and less time being bored), feeding more frequently, or cutting back on grain or other high-energy concentrates. Toys such as a ball or empty one-gallon plastic milk jug can be hung in the stall. Sometimes simply giving the animal a companion in the next stall, or even a smaller animal placed in the same stall, also helps a bored or nervous horse.
In extreme cases, a short term fix may include tying up the horse in its stall, putting on a "cribbing strap" (which prevents sucking in air), putting on a muzzle, or hobbling its feet. However, none of these practices solve the underlying problem, may raise animal welfare concerns, and the animal will resume its behavior as soon as the restraint is removed. The only long-term solution is to give the horse less time in the stall and, preferably, more free turnout time.
Horses may engage in a number of undesirable behaviors when being ridden or driven. These are not "stable" vices, but are often classified as "vices" in terms of being behavior that poses a danger to the animal or its handler. Among these are running away, bucking, and rearing.
- Christie, Julie Christie, (2008). "Horse Behavior and Stable Vices". University of Minnesota Extension (Regents of the University of Minnesota).
- Garner JP, Mason GJ. Evidence for a relationship between cage stereotypies and behavioural disinhibition in laboratory rodents. Behav Brain Res. 2002;136(1):83–92. doi:10.1016/S0166-4328(02)00111-0. PMID 12385793.
- Study on horse masturbation
- Equine Stud Farm Medicine and Surgery. Elsevier Health Sciences. 2003. p. 107. ISBN 0-7020-2130-X. "Masturbation is not a vice; it is best regarded as normal sexual behavior and should not be discouraged."
- Ensminger, M. Eugene. Horses and Horsemanship. Interstate Printers & Publishers; 4th edition (1969). ASIN: B0006BVLOM
- Price, Stephen D., et al. The Whole Horse Catalog. Fireside; Rev Upd edition (1998) ISBN 0-684-83995-4, ISBN 978-0-684-83995-0
- Mills, Daniel. "Recent Advances in the Treatment of Equine Stereotypic Behaviour." Havemeyer Foundation. Web site accessed July 27, 2007 at http://www3.vet.upenn.edu/labs/equinebehavior//hvnwkshp/hv02/mills.htm
- Ryder, Erin. "Hoofing it with John Henry," The Horse, online edition. Web page accessed August 25, 2007