Page 1016 - The Veterinary Care of the Horse

Causes

Factors that precipitate stereotypic behaviour include:
VetBooks.ir • boredom

• stress

• excitement

• frustration

• pain
• digestive discomfort.

Typical situations that occur in stables on a daily basis and may trigger this behaviour
include:

• feeding time, especially if the horses anticipate this and become agitated as the first feeds
appear

• eating high concentrate, low roughage rations: this is an important contributory factor as

horses in the wild graze for many hours of the day
• stabling horses and denying them the opportunity to express normal behaviour patterns is

a source of stress
• other horses in the yard going out on exercise or being turned out

• isolation from other horses

• the introduction of new horses to the stable or field

• any departure from the usual routine
• pain

• being sold.

CRIB-BITING AND WIND-SUCKING

Crib-biting and wind-sucking often occur together. The horse grasps a fixed object with its

incisor teeth and contracts the muscles of the underside of the neck (Figure 22.1) This draws
the larynx backwards and air is drawn into the upper oesophagus. Contrary to common
belief, the air is not swallowed but is expelled. It is the movement of air that produces the

characteristic gulping or grunting noise made by wind-suckers. Some horses crib without
obvious wind-sucking; others can wind-suck without grasping a solid object.