Prolapsed Frog

Heel Bulbs picture to the right.

Note the very hollow area between the heel bulbs, typical of a hoof with weak internal cartilage structure. Especially note the huge, wide, LIVE frog which can not be safely trimmed to the level of the trimmed heels without invading live tissue. This “prolapsed frog” is typical of a weak foot which was shod without added frog support, thereby exacerbating the negative plane coffin bone as the internal hoof structures in the rear of the foot sink toward the ground.

 

This is an example of a thoroughbred hoof with inherently weak structure and consequently a negative plane coffin bone. 

The external "red flag" ,absent of Xrays is the bulge in the dorsal hoofwall which is caused by the toe of the coffin bone being higher than the heel, and pushing forward on the wall.