I googled:)...google knows all:)
Anyway found this and it sure sounds like it fits, IF that shoe is too small.
Corns - A corn on a horse is simply a bruise of the sensitive sole of the foot. The injury causes lameness and is usually accompanied by a red, circular stain where blood has effused underneath the horn. Advanced corns are yellow, infected and become abscesses.
Causes:
Corns are caused by unequal pressure and/or concussion, through conformation defects, over- trimming of heels, shoe heel caulks, short-heeled shoes or un-level shoes. Neglect of the foot or leaving shoes on for long periods without re-setting is also a common cause.
Becky
Thanks for that.... google does know all ;~)