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Unsoundnesses

Equine Conformation Part II: Skeletal Structure

Words of Wisdom

A horse must have structurally correct legsto be a performance athleteWithout good hooves there would be no horse

Most Common Unsoundnesses

Bowed Tendons - tearing flexor tendonsusually in front, low weak pasterns, deep surface

Splints - pulled metacarpal ligamentCa deposits on upper cannon bone - offset knees

Navicular - erosion of distal sesamoid in heeloften steep pasterns, small foot, contracted heels

Laminitis - chronic founder, damaged laminaeoften obesity, over eating, concussion

Spavins - hock problems, posty or sickle hocked

Definitions

UnsoundnessAny deviation in structure or function that interferes with a horse's intended use or performance

BlemishesAbnormalities which do not affect the intended use of the horse

Definitions continued

Serviceably SoundStructural problems/deviations which may have only limited affect on the horse's ability to perform

Unsoundnesses of the Foreleg

carpal chips (big knees)splintsbowed tendonssore suspensoryligamentsesamoid injuryringbone

Unsoundnesses of the Rear Leg

stifle lockthoroughpinscapped hockspavins

bogblood bone

curb

Unsoundnesses of the Foot

ringbonenavicularlaminitissidebonecracks - quarter, sandbruised solesthrush, abscesses, punctures, gravel

Front legs: Front view

Forelimbs bear ~ 65% of horses weight

Due to amount of weight on the front leg, injuries can result from trauma and concussion

Front legs

Need proper bone length and angleWidth of toes on ground = width of origin in chestCannon bone should be centered on knee and fetlock

Deviations: Front view

“pigeon-toed” = toes pointed in"splay-footed“ = toes pointed out

Deviations: Front view

Base narrowHorse stands closer at ground than at origin of legs in the chestToed in or toed outTypical of horses with large muscle mass

Deviations: Base Narrow

Predisposed to landing on outside of hoof walls = Extra weight on outside of hoof causing

Ring bone: bony enlargement of surrounding bones of pastern Side bone: ossification of lateral cartilage (Ca accumulation) Heel bruising

Base Narrow

Deviations: Front View

Base wide: Conformation positions horse's feet wider at ground than at their origin in chest

Usually accompanied by feet that are toed-outNarrow chested horses

Weight on inside of hoof leading to ring bone and side bone

Deviations Base Wide

Deviations: Front View

BowlegsPresents entire knee in an outward deviationIncreases tension on outside of leg

Knocked-kneed/ Close kneed

Entire knee set to inside of straight line from chest to toeGenerally with toed-out

Deviations: Front view

Bench-kneesCannon bones set too far to the outside of kneeIncrease possibility of splints: bony enlargement in groove formed by splint and cannon bone

Front legs: Side view

Front column of bones = appropriate slope and angle of shoulderCorrect line from center of scapula to front edge of knee and bisects hoof

Deviations: Side View“Camped under”

Forelimb is too far under bodyPrevents long, fluid stridePredisposes to unsoundness

> Pressure on ligaments and tendons

Deviations: Side View

“Camped Out”Forelimb too far forward and away from body> Concussion and stress on knees, ankles, and hoovesOften associated with laminitis: inflammation of laminae in hoof wall; rotation of coffin bone

Acute, painful, hot laminae

Deviations: Side View“Camped Out”

Predisposed to laminitis: Inflammation of laminae in hoof wall; rotation of coffin bone

Other causes of laminitis besides “camped out”

– Nutritional = overeating– Grass foundered = lush

pasture– Infections– Road founder =

concussion in trailer over time

Deviations: Side View

“Camped Out”Predisposes to navicular disease: Degeneration or roughening of distal sesmoid bone = fluid loss

Soreness in heels

Deviations: Side View

Other causes of Navicular

Small feetTrimmingMore vertical in pasterns

Deviations: Side View“Over-at-the-knees/buck-kneed”

Knee set too far forward in relation to legTypically capable of long performance life

“Back-at-the-knees/calf-kneed"

Knees back behind the vertical of legExtremely serious (knees hyper-extend)

Deviations Front or Side View

PasternsIdeal pastern is moderate in lengthAngles ~ 45 degrees in front and 50 degrees in back short, steep pasterns = not normal "cushion" found in ideal horse

get a rough, choppy strideGreater frequency for lameness due to concussion of entire front column or bones

Too long pasterns = weak, injure ankles, tendons and ligaments

Rear Legs: Back View

Line from buttocks to ground: bisect gaskin, hock, and hoof gives = distribution to decrease strain on legs

Deviations of the Rear Leg

Cow hocked: Bowed in at hocks and cannon bone

Hocks set too close together, feet widely separatedTend to be weak in work off of haunches (i.e. stopping, turning, sliding)

Deviations of the Rear LegSickle-hocked: too much of an angle in the hock joint

Predisposed to curbs: Enlargement below point of hock (ligaments, tendon sheath, skin)

Post-legged: too straight in back

Predisposed to stifled: upward fixation of patellaPredisposed to spavins:

Deviations of the Rear Leg

Bowlegged: toed-in behind

Hocks too far apartUsually poor athletes

Rear Legs: Side View

Line from buttocks to ground: touches hocks, is parallel to cannon bone and is slightly behind heel

Balance & Soundness