Arid summer weather can change the appearance of a horse's hooves.
It's the middle of summer and your horse's hooves seem to be sending an SOS. The soles and frogs are peeling and flaking.
Yet a bit of examination may reveal that the cause is simply a seasonal change in footing.
Equine hooves typically get plenty of moisture in the spring. As a result, the horn that emerges is very pliant and relatively soft. In the summer, drier conditions stimulate the growth of much harder, denser horn. The zone between the soft and hard growth eventually causes the frogs and soles to crack and peel.
The condition is temporary, and regular trimming will prevent it from causing your horse any trouble. If, however, be becomes lame or his hooves develop a very foul odor indicative of thrush, consult your veterinarian.