Have you ever been told your horse has flat feet and/or thin soles? Did you know both of these problems could actually be the result of hoof flaring? This blog will illustrate how flaring decreases hoof concavity and sole thickness.
Let’s start by making sure you have a clear understanding of what what is meant by hoof concavity. Hoof concavity refers to the inward curving surface of the bottom of the hoof. Hoof concavity exists because the bottom of the coffin bone is concave. You already know from my previous blogs, the sole tubules grow from the bottom of the coffin bone; therefore, the sole region’s concavity will match the coffin bone’s concavity in a healthy, well-balanced hoof. Click images below to enlarge:
When a hoof is flared the entire hoof loses vertical height as the capsule wall bends and is pried outward from the sole region. This loss in vertical height results in the sole region becoming closer to the ground. The worse the flaring, the more the hoof will lose vertical height and the closer to the ground the sole becomes. Image below shows how a flared hoof loses vertical height causing the sole region to become closer to the ground:
In a healthy, non-flared hoof the capsule wall provides support to the sole tubules—keeping them upright and compact. When the capsule wall flares outward the sole tubules lose the support provided by the capsule wall and begin bending and moving outward as well. This results in the sole tubules becoming less vertical and less compact which decreases the thickness of the sole as well as the concavity of the hoof.
So, not only is the sole closer to the ground in a flared hoof, but the sole is thinner as well! This means much less protection for the coffin bone.
I will add coffin bones have varying amounts of concavity; a hoof with a less concave coffin bone will always have less concavity than a hoof with a more concave coffin bone. The point of this blog is to show that flaring reduces concavity in ALL hooves—making it especially important to eliminate flaring in hooves with less concave coffin bones!
In the next blog, we will take a look at the hoof from the bottom to learn how flaring can increase the chance of white-line disease and abscesses.