To say that the equine hoof wall is an amazing structure is a gross understatement. It must withstand a multitude of destructive forces from the environment — both man made and natural — and extreme concussive forces trying to tear it apart. Given these circumstances, it’s no wonder that failures occur.
As farriers, we know the equine hoof wall is composed of keratin. It’s produced by papillae at the coronary band forming tubules that are “bonded” together, which gives them amazing vertical strength, yet maintains flexibility.
Unfortunately, some horses do not get a piece of the genetic lottery and are born with less-than-stellar wall thickness and strength. While a thick hoof wall has a better chance of remaining crack free, it’s no guarantee against wall failure.
Wall failure doesn’t usually just happen. Cracks can be caused by a number of factors including neglect, an alternately wet-dry environment, traumatic injury, infections, poor hoof wall quality, poor horseshoeing and twisting of the hoof capsule.
Cracks occur when there is separation of the tubules, often resulting in acute pain. The result is that now there is movement on both sides of the crack constantly irritating the papillae that produce healthy tubules and preventing formation of healthy horn. Consequently, the primary repair methods require stabilizing the wall on either side of the crack and preventing movement at the coronary band.