Hoof cracks that start in the center of the dorsal hoof wall
can be caused by leverage. Generally, if they start from the bottom and
move upward, they are caused by leverage from the toe being too long (meaning
the distance from the TRUE apex of the frog to the end of the toe as viewed
from the bottom of the hoof).
The only thing that will stop/heal the crack permanently is
to remove the leverage, consistently for about 9-12 months while new hoof wall
grows down/outward.
