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
Questions?