This horse has severe foot problems, medial lateral out of balance and under run heels. When the heels are too far forward then the tendons and ligaments become weight bearing instead of the bone structure. This causes the bulbs of the heels to rotate downwards under the weight, from lack of support.
This shows a shoe that is too small, and not square with leg.
This shows right hind too small shoe, turned to inside of foot.
This shows severe cracks from improper balance,
due to long toe and low under-run heel
The same feet as first picture after medial lateral balance and shortening the toe.