Crack in the hoof wall parallel to horn growth in the region of the heels or the quarters. In general usage, cracks in the heel region are also called quarter cracks.

A North American breed of horse, bred to race over a quarter of a mile. It is the most popular breed of western horse and is well represented in all western sporting disciplines.

Outer (lateral) and inner (medial) section of the hoof wall beween the toe and the heels.

An infection of a collateral cartilage that leads to necrosis and the build up of purulent fluid (pus) around the cartilage which will eventually drain in the region of the coronary band. Without treatment, the draining tract (fistula) will persist.