The horse’s hoof is an incredibly adaptive structure. It changes to meet whatever is being asked of it. As with any animal, environment influences physical expression. So then terrain develops the specific internal structures of a horse hoof, ultimately determining the level of soundness.
Factors in a horse’s living environment directly benefit the strength and resiliency of the hoof’s form. These factors are especially influential during the early formative years, from birth to five years of age during maturation of the foot. The surface a horse places its foot upon all day, every day is one of the critical elements of soundness.
When a foal is born, the foot has just begun to develop in its environment. At the back of a newborn hoof is a lump of undifferentiated fat. Within that lump of fat is a very important nerve centre that allows the horse to “feel” the terrain under him.
Miles and miles of twisting, flexing and expansion of the hoof capsule as the foal grows ensures an ongoing relationship between the hoof, the horse, and environment. Cyclic weighting and unweighting with each step conditions internal structures of the hoof.
Lateral cartilages form the foundation for the back half of the foot. At birth they are a one-sixteenth inch thick and exist only on the sides of the hoof capsule. By the time a horse reaches adult weight, these cartilages should be almost an inch thick and form a strong supportive, yet elastic, “floor” at the back of the hoof.
The digital cushion is a structure that fills the space between the heel bulbs and the frog. Miles and miles of frog stimulation develops a resilient, elastic type of fibro-cartilage in this space, becoming the digital cushion. By the time the horse reaches adult weight, the digital cushion should be a solid mass of fibro-cartilage, offering enough protection for the nerves to withstand the impact force of an adult horse.
Without development of these internal structures, horses reach adult weight with “baby feet.” These result in what is currently referred to as “small-foot syndrome.” Their digital cushions are still mostly comprised of fat and their lateral cartilages are very thin. Horses with immature or weakly developed caudal heels often land toe-first to avoid weighting their heels directly, resulting in sensitivity and a shortstrided, stiff movement.
Development of the structures at the back part of the hoof is integral to dissipation of concussive forces during weight bearing. If improperly structured, concussive shock is directed up through the body. The rest of the body is not meant to deal with these forces and over time vibrational chatter sores bodies and joints. Shock absorption is key to functional hoof capsules.
VARIETY OF SURFACE BEST
The ideal environment for the development of a horse’s hoof allows for plenty of movement and a variety of footing surfaces. Seasonal flux naturally assimilates variation by offering days of frozen terrain and days of muddy surfaces. All can be beneficial for development since different footings develop different aspects of your horse’s feet.
Soft surfaces such as grass, dirt, sand or shavings cushion your horse’s feet. It encourages movement that is essential to stimulate the development of healthy sole, heels, and walls. Yet too much soft terrain doesn’t challenge the foot.
Pea-sized gravel can be incorporated and acts to distribute pressure evenly. Hard gravel can toughen the wall, frog, and sole while also burnishing edges. Mud can be of advantage as well, in moderation, as it brings moisture to the hoof, encouraging shedding of dead sole and loosening and lifting of overlaid bars.
Remember during your childhood at school’s end in June you would gingerly pick your way through the outdoors in bare feet, yet by September you were nimble barefoot, even on the roughest of surfaces. Horses, as well, develop and condition their hooves with each step.