Page 116 - January 2022

EQUINE HEALTH
A stereotypy is a ritualistic and repetitive behavior that serves no known purpose that can be associated with a trigger such as feeding time.
“Endorphin levels in his bloodstream rise when he performs stereotypic behavior. When these levels become high, he seems satisfied . . .”
LOCOMOTOR STEREOTYPIES
Stall or fence walking and weaving are
the most common ambulatory patterns of stereotypies; the horse moves in a constant repetitive rhythm. A weaver remains stationary but sways back and forth, shifting weight from one foreleg to the other, usually standing in the same place in his stall or fence corner in a paddock every time he does it.
He may just shift his weight, rocking from side to side on his front feet, or may shift
his whole forehand back and forth--almost pivoting in place. Some horses just bob their heads back and forth continually. Weaving usually begins because of frustration at being confined or separated from other horses, or from inability to graze. Weaving becomes
the horse’s way of coping, especially when he discovers it can relieve stress and frustration through the release of endorphins in his brain.
Endorphin levels in his bloodstream rise when he performs stereotypic behavior.
When these levels become high, he seems satisfied and stops weaving. When endorphins drop to a low level, he starts up again and becomes very intense in his weaving until the endorphin levels rise.
Similarly, a stall walker constantly circles his stall or paces back and forth in a certain pattern. A fence walker may pace in front of a gate or along one side of his paddock, usually the fence nearest other horses.
WHAT IS A STEREOTYPY
By definition, a stereotypy is a ritualistic and repetitive behavior that serves no known purpose. Stereotypical behavior is seen in about 15% of domestic horses and can be classified into two types--locomotion and oral. The amount of time a horse spends in these activities varies from horse to horse and may be random or associated with a trigger such as feeding time; many horses paw or kick their stalls or become more intense in their cribbing or weaving activities.
One of the main needs, and comforts, of any animal or human is food. When stressed psychologically, many individuals resort to some kind of replacement behavior that takes the form of an oral habit/compulsion, since eating is a way of coping with stress. Cribbing may develop originally from the horse’s compulsion to eat--chewing wood if nothing else is available--to ease his stress. Simple wood chewing can progress to cribbing with the horse pressing a wooden surface with
his top incisors, letting his lower jaw hang slack, flexing his neck, opening his throat and pulling back with his mouth open-- swallowing air with a grunting sound.
Once a horse starts cribbing, it quickly becomes an addiction. This compulsion can sometimes be triggered by eating sweet feed. Researchers feel that some types of food may be involved in development of stereotypies. Most of the oral stereotypies are related to a desire
to eat, and restricted feed intake - the artificial high-energy diet we feed confined horses, with very little roughage - may be as much a cause as is the confinement and isolation.
The abnormal behavior develops over
time and then becomes a pattern. If a horse does not feel full, he tries to go through the motions that normally would lead to eating such as chewing on something, which may then develop into cribbing. Most cribbers do their most intensive cribbing around mealtime, while impatiently waiting to be fed or when watching other horses eat.
“There are studies suggesting stereotypic horses learn associations more quickly and stronger, and take longer to ‘unlearn’ it, than non-stereotypic horses.“
A weaver remains stationary but sways back and forth, shifting weight from one foreleg to the other, usually standing in the same place in his stall or fence corner in a paddock every time he does it.
114 SPEEDHORSE January 2022