Laminitis is the condition that causes founder. Laminitis is when the soft laminae tissue in the hoof begins to die due to lack of blood flow. The laminae holds the coffin bone in place and attaches it to the hoof wall. Once the laminae dies, it can no longer do its job of holding the coffin bone in place. As the condition progresses (and if left untreated) the coffin bone can begin to rotate and slip downward toward the sole of the foot and even through the sole of the foot.