What forms from a sole ulcer?

• A. Granulation tissue
• B. Prolapse corium
• C. Callus
• D. Abscess

Answer: (B)

A sole ulcer is a defect in the solar horn where the underlying corium (the sensitive tissue under the hoof) becomes exposed due to pressure and injury. When this ulcer progresses, the corium itself can bulge outward through the damaged sole—this is the prolapse of the corium. That prolapse is the hallmark feature of a sole ulcer, reflecting the loss of protective horn and exposure of vascular, sensitive tissue. Granulation tissue may later form as part of healing, but it is not the defining lesion itself. A callus is a thickened keratin layer from chronic pressure, not the ulcerous exposure of corium. An abscess involves a pus-filled pocket, which is a different pathology from the typical sole ulcer.