These are the result of inadequate or uneven wearing of the horn of the hoof. Any disease causing lameness may result in deformity or uneven weight bearing, or it can occur simply from constantly being on soft ground.
The hoof is misshapen by overgrowth of horn of the wall and toe. Lameness may be present which may be a cause or a consequence of overgrowth.
Reestablish the normal shape of the hoof by paring with secateurs to remove excess horn.
Correct any underlying lameness problem. Running animals on abrasive surfaces such as concrete yards and bitumen roads from time to time may assist prevention.