In double sole, one sole is present while a new sole grows beneath, ie, there is complete shut-down of horn production for an undetermined short period of time.
A new sole grows beneath an existing one when fluid forms between the dermis and epidermis. This fluid can result from bruising of the sole under conditions such as prolonged walking on rough roads. The fluid may be pus from a subsolear abscess. Double sole has been seen in cattle suddenly changed from a mainly forage diet to one rich in concentrates. Double sole can be confused with underrunning of the heel, which is a frequent sequela of white line disease. Double sole has also been seen after feeding moldy hay.
Treatment is simple unless mismanaged. The abaxial wall must remain completely intact and only a portion of the sole covering the bulb cut away. The sole beneath is extremely soft and vulnerable to damage; therefore, the animal should be confined to a well-strawed stall until the new horn has hardened, after which more of the sole may be removed.
Sudden changes in the quality of the forage should be avoided.