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Horse Behavior

Lynne M. Seibert DVM, MS, PhD Diplomate ACVB

Equus caballus • Organized into large herds • Ancestors were open plains grazers • Majority of time spent grazing – 60-80% of time budget

• Free-ranging horses are descendents of domestic stock – No longer any truly wild horses – Feral

Social Organization • Family (harem) bands – Several mares – Offspring up to 2-3 years of age • Both fillies and colts leave natal band

– One or more adult breeding males

Harem Stallion – Stays with band all year – Herds and protects – Leadership limited to defense from intruders – Drive away mature male offspring

Social Organization • Bachelor bands – Males not associated with family bands

Home range • Home ranges of multiple bands overlap • Not typically territorial – Only when there are resources that are • valuable • defensible

Perception • • • • •

Visual acuity less than humans Field of vision wider than humans Auditory perception similar to humans Sound localization is poor Muzzle most tactile sensitivity

Visual Signals • Ears – Tightly back against the head: threat – Forward and erect: interest – Bent to the side: resting or submissive

• Tail – Raised above the back: excitement – Tucked against the body: fear, submission, or rest

Aggression • Ears back

Aggression • Threat to bite • Bite

Aggression • Supplant or • Approach/Avoid

Aggression • Threat to kick

Aggression • Kick

Aggression • Chase

Aggression • Snaking – Driving, herding

• Ears flat, back • Head down

Dominance • Hierarchy is linear up to 5 or 6 individuals • Larger herds will have more complex relationships – Triangles – Coalitions

Dominance • Contrary to popular myth and subjective studies, studies that focus on win/loss results in dyadic interactions have found that stallions are often not dominant to mares

Dominance • Offspring of highranking mares tend to be high-ranking • Offspring of lowranking mares tend to be low-ranking • ??Genetics or Experience??

Other effects? • Adult horses are always dominant to juveniles • Multi-stallion bands dominant to singlestallion bands

Other effects? • No consistent effect of – Weight – Height – Specific age – Gender

Champing • • • • •

Aka snapping, tooth clapping Facial expression of foals Peaks at 2 months of age Directed to adults, mostly stallions Appeasement or displacement behavior

Olfactory Communication • • • • •

Recognition of group members Information about reproductive state Mare-foal recognition Stud piles Urine marking

Flehmen • More common in males – stallions > colts > fillies > mares

• Vomeronasal organ – Paired tubes inside base of nasal septum – Projections to amygdala

• Response to urine of estrus mare – Normal sexual development

Social conflict • Stocking density • Limited resources • Integration of new horse into established herd

Human-directed Aggression • • • •

Fear Hormone-related Pain Dominance ?

Coprophagy • Normal in foals • Not normal in adults

“Stable Vices” • • • • • • • • •

Cribbing Wood chewing Weaving Wall kicking Tongue rolling Stall circling Pawing Head shaking Self-directed aggression

Stereotypy • Unvarying, repetitive behavior pattern that is constant in form, has no obvious goal or apparent function and occurs in a predictable sequence • Prevalence in horses: 7.5 - 30%

Stereotypy • Behavior begins due to frustration, conflict, or lack of stimulation • Develops into stereotypy • Generalizes to other contexts • Triggered by progressively lower level of arousal

Cribbing • Grasping a horizontal surface with incisors, flexing neck, and inhaling, but not swallowing air

“Stable Vices” • Do not occur in feral populations • There is no evidence that they are learned • Evidence of environmental effects – Horses kept in stalls with minimal opportunity for contact

Environment • Lack of social interaction with other horses • Lack of exercise • Non-straw bedding

Effect of Diet • Low roughage rations • Concentrate decreases hind gut pH • Onset of cribbing associated with start of concentrate provision in foals

Breed and Gender Effects • Thoroughbreds – Cribbing, weaving, head shaking

• Arabians – Stall walking

• Stallions – Cribbing – Weaving – Self-directed aggression

• Geldings – Head shaking

Treatment • Keep in social groups as much as possible • Remove from stall • Increase visual contact with other horses • Allow opportunity for foraging • Later weaning • High roughage diet

Physical Prevention • Cribbing collars – Cribbing increases when collar removed – If cribbing prevented, horses ate more – If cribbing and foraging prevented, horses show marked distress

Treatment • Once established, horse may continue with problem behavior even when put in highly enriched environment • Evidence of response to various drugs that work on compulsive disorder in other species • Currently cost-prohibitive in horses

Self-Injurious Behaviors • Flank-biting • More common in stallions • Sexual frustration?

Trailering Problems • Failure to load – Properties of trailer – Prior experience

• Scrambling

Trailering Problems • • • •

Train to move when touched Desensitization and counter-conditioning Trailer design Social facilitation

Mare – Foal Interactions • Mare bonds to foal 1st hour post-partum – Do not disturb in 1st hour – Do not remove fetal membranes

• Foals are followers

Recumbency Response • Mare stands beside recumbent foal • 1st week: within 3 ft 85% of time • 9th week: within 3 ft 40% of time • Social facilitation

Foal Rejection • Accepts foal, but refuses to nurse • Fear of foal, runs from foal • Foal-directed aggression • Higher incidence in Arabian mares

Foal Rejection - Treatment • • • •

Restrain mare Relieve pressure on udder Bottle-feed in mare’s presence Use threat from other horse or dog to stimulate maternal behavior • Medications – Tranquilizers – Hormones

Behavior Problems • Stallions – Inadequate libido – Unruly breeding behavior

• Geldings – Stallion-like behavior – Up to 50% regardless of age at castration


Horse Behavior