What’s going on inside?
A foal is born with his coffin bone high up in the hoof capsule, and the connection between the epidermal and dermal laminae is tight. This connection is what holds the internal structures of the hoof exactly where they need to be. The position of these structures – high in the hoof capsule – creates a concave shape on the sole. The concavity represents a well-connected hoof and correct anatomy. The coffin bone itself is not flat, but has a slight curve to it, and the external structure follows this shape. This tight connection remains strong and intact as the horse grows, unless influenced by external factors such as the ones humans introduce: poor hoof care, premature or unnecessary shoeing, restricted movement and rich diets all contribute to the declining health of the hoof.
When a horse moves and the hoof comes into contact with the ground, the hoof spreads and flexes to absorb the impact of the skeletal structure descending within the hoof capsule under the horse’s weight. The concave structure of the hoof is what allows the hoof to expand and contract during movement and assists with stability and balance. As you can imagine, a flat-footed horse does not enjoy the same benefits.
What causes flat feet?
In racehorses, premature shoeing disrupts the natural growth and development of the hoof structure, and can therefore result in flat feet. An unbalanced or incorrect diet can cause major problems for a horse’s hooves. The wrong food can mean too much sugar or grain, or mineral imbalances. This can in turn cause the connection between the epidermal and the dermal laminae to be compromised and weakened. The structure then sinks and a flat foot develops.
Further to these causes, we add peripheral loading. Peripheral loading means that the hoof wall bears most of the weight in the hoof. The degree of peripheral loading depends on the type of shoeing or trim. Studies have shown that the greater the peripheral loading, the worse the blood flow throughout the hoof capsule. Shoes that do not support the frog and sole cause the horse to carry his weight on the hoof walls, which results in the epidermal and dermal laminae pulling away from each other. The skeletal structure then further ‘collapses’ and pushes the sole out.
A weak heel causes the horse to land toe first, which sets him up for all sorts of problems down the line, like the development of navicular, and contributes to further sinking of the skeletal structure to the bottom of the hoof capsule.
With all these problems combined, the entire hoof structure is compromised, leading to decreased circulation, inflammation, and improper hoof mechanism and movement. The end result is a flat-footed horse who will develop lameness, which could be irreversible in serious cases.
The full article appears in the The Winter Guide issue of HQ (July 124) > Shop now