Healthy hoof walls are smooth; have a light sheen; are free of prominent growth rings; and lack flares, cracks, and bruising, Taylor said.
The presence of prominent growth rings can indicate a number of problems, including reduced blood perfusion in the corium (the hoof’s dermis, or the middle soft tissue layer that connects the coffin bone to the rigid hoof capsule and contains the hoof’s blood supply). resulting from abnormal hoof loading, diet changes, exercise intensity, or systemic disease. Growth rings can also indicate a negative palmar/plantar angle; Taylor said growth rings in these horses are “often wider in the toe region and narrower in the heel region due to uneven blood flow caused by overloading of the heel.”
Chronic and excessive overloading of the hoof wall also can cause flares or cracks, Taylor said.
Hoof wall bruising is indicative of trauma, she said, and bruises can form near the coronary band when ground reaction force pushes the hoof capsule against the coronary region’s vascular (blood vessel-rich) tissue. While some isolated bruises can be caused caused by a single acute event, others—typically seen as a wide band of bruising—are an indication of chronic trauma, such as laminitis, Taylor explained.