10/15/2025
THE UNSOUNDNESS WE BREED FOR – FACTS BEHIND THE FASHION
BREEDING HAS CHANGED THE HORSE WE SEE
Across European Warmblood populations, the average horse has grown roughly 1–2 cm taller per decade since the 1980s. Mean wither height for many modern stallions now sits around 169–172 cm—almost a full hand taller than forty years ago. Body mass and frame have grown to match, increasing the load per square centimetre of hoof.
Other breeds show the same pressure from fashion, though in different directions:
– Thoroughbreds have become taller, finer-limbed, and faster, with smaller hooves relative to body size.
– Arabians have stayed similar in height but selection for extreme refinement has narrowed bone and hoof width.
– Native ponies (Welsh, Highland, Dales, Fell) have mostly retained strong proportions, yet show lines sometimes favour flatter feet and lighter bone for “type.”
Bigger or more refined doesn’t mean stronger. A horse with more frame on the same-sized feet simply channels more force through the digital cushion, deep digital flexor tendon (DDFT) and navicular region—raising the risk of heel pain, micro-damage and early joint wear.
GENETICS SET THE BLUEPRINT, MANAGEMENT BUILDS THE STRUCTURE
Hoof shape and proportion are moderately heritable—studies in Warmbloods, Thoroughbreds and Standardbreds place heritability between 0.15 and 0.30 for traits such as hoof angle, heel height and toe length. That means breeding can move a population gradually toward better (or worse) feet, but management still does most of the work.
Feeding, trimming, movement, footing and environment shape how that genetic potential is expressed. A foal from excellent bloodlines can still grow weak, low heels if minerals are out of balance or trims come too late. Conversely, good hoof care and nutrition can help offset less-than-ideal genetics.
WHAT “LONG TOE / LOW HEEL” ACTUALLY MEANS
These aren’t aesthetic details. They are mechanical imbalances.
A long toe delays break-over and increases tension in the DDFT.
Low or underrun heels both shift load forward, compress the soft tissues of the heel, and reduce shock absorption—but they’re not identical.
Low heels describe reduced heel height—heels that sit too close to the ground.
Underrun heels describe a shallower heel angle where the heel tubules grow forward under the foot.
One affects height, the other orientation, yet both lead to the same functional problem: forward weight shift, loss of heel support, and increased strain on the navicular apparatus and deep digital flexor tendon.
Veterinary imaging studies across Warmbloods and Thoroughbreds consistently show a link between these heel patterns and a higher incidence of navicular changes and DDFT lesions.
MANAGEMENT MATTERS—FROM FOAL TO ADULT
Research is clear:
– Steady, moderate growth and balanced mineral intake reduce developmental joint problems.
– Copper and zinc are essential for horn and connective-tissue strength; so is a proper calcium-to-phosphorus ratio (about 1.5 : 1).
– Regular early hoof balancing encourages correct heel formation.
– Controlled exercise from weaning onwards supports bone density and cartilage development.
Rapid growth, mineral imbalance or restricted movement increase the risk of osteochondrosis (OC/OCD), a condition with heritability between 0.10 and 0.40 depending on joint and breed. Even genetically “clean” foals can develop lesions under poor management; well-managed foals from risk lines often stay sound.
TOOLS THAT ALREADY EXIST TO IMPROVE SOUNDNESS
– D-OC genomic index (KWPN): estimates a horse’s genetic risk for osteochondrosis.
– PROK radiographic screening: detects subclinical joint changes before licensing.
– WFFS testing: now routine across most Warmblood registries to prevent carrier-to-carrier matings that produce non-viable foals.
– Hanoverian, Holsteiner, Swedish and Danish soundness indices: integrate X-ray and performance data into breeding evaluations.
These are not bureaucratic steps; they are concrete levers for selecting health alongside talent.
BEYOND WARMBLOODS – OTHER BREED TRENDS
– Thoroughbreds: Selection for speed has produced lighter bone, flatter soles and small feet relative to body mass—traits linked with distal limb injuries.
– Arabians: Often exhibit high hoof angles and narrow feet, which can perform well in endurance if managed carefully but reduce load-bearing surface.
– Stock breeds (Quarter Horses, Paints): Certain halter lines show upright pasterns and thin soles, predisposing to heel bruising and navicular syndrome.
– Native ponies: Retain some of the best hoof-to-body proportions, but modern showing trends occasionally prioritise cosmetic neatness over function.
Wherever the pressure for looks outweighs function, unsoundness follows.
FOR OWNERS AND CARE TEAMS
Good hoof care supports what genetics provide.
Regular maintenance, appropriate surfaces, and nutritional balance build resilience over time.
Shoes or barefoot isn’t a matter of ideology—it’s a management choice. A well-fitted shoe can protect a foot under load; an unbalanced one can cause damage. Barefoot management can build strength if the trim, surface and diet support it—but can expose weakness if they don’t.
THE TAKEAWAY
Breeding can shape type.
Genetics can fix proportions.
Management and hoof care decide the outcome.
Fashion can push horses toward extremes—longer limbs, finer bone, taller frames—but only the daily care determines whether those horses stay sound.
The real measure of progress isn’t the photo at five years old; it’s the horse who still walks out confident and comfortable at fifteen.
Until soundness is valued as much as movement and glamour, we’re not improving the horse—we’re just repeating the same mistake in a prettier package.
