It takes nearly a year for the hoof to grow down from the coronary band to the ground. Therefore, anything that happens to the horse — whether specific trauma to the foot or a systemic problem — can affect the health of the hoof for a long time. Add into that equation that many horses genetically have feet that are not equipped to handle the day-to-day stresses of their work, and a bad shoeing job every now and then, and you have the ingredients for disaster.

The wall of the hoof grows down from the coronary groove from sensitive papillae. These cells are cornified (hardened) and form the horn wall of the hoof. Each papilla grows one tubule, taking approximately one year for that tubule to grow from the coronary band to the bottom of the foot. The matrix (a cementing substance between the tubules) that surrounds the tubules also is cornified tissue that grows from the secondary laminae, forming a network with the tubules.

The three basic layers of the hoof wall from outside to inside are the stratum externum, stratum medium, and stratum internum. The stratum externum is only a few millimeters thick and is somewhat rubbery near the coronary band and gives the exterior of the foot a "waxy" look. The purpose of this wax-like coating is to prevent dehydration of the hoof structure. It is important not to remove too much of this protective layer. Stripping of this protective layer can be caused by caustic chemicals, such as turpentine used to remove hoof polish, or excessive removal of the material by rasping during the shoeing/trimming process.

The bulk of the hoof wall is made up of the pigmented horn tubules of the stratum medium