Unsoundnesses. Equine Conformation Part II: Skeletal Structure

Transcription

1 Unsoundnesses Equine Conformation Part II: Skeletal Structure

2 Words of Wisdom A horse must have structurally correct legs to be a performance athlete Without good hooves there would be no horse

3 Most Common Unsoundnesses Bowed Tendons - tearing flexor tendons usually in front, low weak pasterns, deep surface Splints - pulled metacarpal ligament Ca deposits on upper cannon bone - offset knees Navicular - erosion of distal sesamoid in heel often steep pasterns, small foot, contracted heels Laminitis - chronic founder, damaged laminae often obesity, over eating, concussion Spavins - hock problems, posty or sickle hocked

4 Definitions Unsoundness Any deviation in structure or function that interferes with a horse's intended use or performance Blemishes Abnormalities which do not affect the intended use of the horse

5 Definitions continued Serviceably Sound Structural problems/deviations which may have only limited affect on the horse's ability to perform

6 Unsoundnesses of the Foreleg carpal chips (big knees) splints bowed tendons sore suspensory ligament sesamoid injury ringbone

7 Unsoundnesses of the Rear Leg stifle lock thoroughpins capped hock spavins bog blood bone curb

8 Unsoundnesses of the Foot ringbone navicular laminitis sidebone cracks - quarter, sand bruised soles thrush, abscesses, punctures, gravel

9 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

10 Front legs Need proper bone length and angle Width of toes on ground = width of origin in chest Cannon bone should be centered on knee and fetlock

11 Deviations: Front view pigeon-toed = toes pointed in "splay-footed = toes pointed out

12 Deviations: Front view Base narrow Horse stands closer at ground than at origin of legs in the chest Toed in or toed out Typical of horses with large muscle mass

13 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

14 Base Narrow

15 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-out Narrow chested horses Weight on inside of hoof leading to ring bone and side bone

16 Deviations Base Wide

17 Deviations: Front View Bowlegs Presents entire knee in an outward deviation Increases tension on outside of leg Knocked-kneed/ Close kneed Entire knee set to inside of straight line from chest to toe Generally with toedout

18 Deviations: Front view Bench-knees Cannon bones set too far to the outside of knee Increase possibility of splints: bony enlargement in groove formed by splint and cannon bone

19 Front legs: Side view Front column of bones = appropriate slope and angle of shoulder Correct line from center of scapula to front edge of knee and bisects hoof

20 Deviations: Side View Camped under Forelimb is too far under body Prevents long, fluid stride Predisposes to unsoundness > Pressure on ligaments and tendons

21 Deviations: Side View Camped Out Forelimb too far forward and away from body > Concussion and stress on knees, ankles, and hooves Often associated with laminitis: inflammation of laminae in hoof wall; rotation of coffin bone Acute, painful, hot laminae

22 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

23 Deviations: Side View Camped Out Predisposes to navicular disease: Degeneration or roughening of distal sesmoid bone = fluid loss Soreness in heels

24 Deviations: Side View Other causes of Navicular Small feet Trimming More vertical in pasterns

25 Deviations: Side View Over-at-the-knees/buckkneed Knee set too far forward in relation to leg Typically capable of long performance life Back-at-the-knees/calfkneed" Knees back behind the vertical of leg Extremely serious (knees hyper-extend)

26 Deviations Front or Side View Pasterns Ideal pastern is moderate in length Angles ~ 45 degrees in front and 50 degrees in back short, steep pasterns = not normal "cushion" found in ideal horse get a rough, choppy stride Greater frequency for lameness due to concussion of entire front column or bones Too long pasterns = weak, injure ankles, tendons and ligaments

27 Rear Legs: Back View Line from buttocks to ground: bisect gaskin, hock, and hoof gives = distribution to decrease strain on legs

28 Deviations of the Rear Leg Cow hocked: Bowed in at hocks and cannon bone Hocks set too close together, feet widely separated Tend to be weak in work off of haunches (i.e. stopping, turning, sliding)

29 Deviations of the Rear Leg Sickle-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 patella Predisposed to spavins:

30 Deviations of the Rear Leg Bowlegged: toedin behind Hocks too far apart Usually poor athletes

31 Rear Legs: Side View Line from buttocks to ground: touches hocks, is parallel to cannon bone and is slightly behind heel

32 Balance & Soundness