Mule Hooves Versus Horse Hooves

It's very interesting to me to learn more about the physical differences between mules and horses.  The ears may be the first thing you think about but upon examination, the hooves are markedly dissimilar also. 

The first thing you may notice about mule hooves (first photo) is how boxy and improbably upright they are, when viewed from the front. The first shot is Josie the mule, and the second is Willow the Saddlebred. 

From the side, mule and horse hooves look about alike, although the mule's angles are usually more upright. 

Looking at the sole (next to last photo) it's easy to see how the mule's hoof is more oblong, rather than round like a horse's.  Mule feet are said to be tougher than horse's and less given to lameness, and I guess it must be so, because a mule will usually have smaller feet than a horse of the same size, and it's not uncommon for a horse-sized mule to wear pony shoes (if shoes are needed, which is not usual).   The mule hoof also has a thicker wall near the toe and heel, and the frog can extend a little behind the hoof. 

Of course, I think Willow's feet are uncommonly big and beautiful, but I may be a little prejudiced!