HORSE

Chestnuts

Chestnuts evolved from a third toe 

Chestnuts are flat, crusty, and devoid of hair. They are located on horses' legs just above their  knees on its front legs and below the hocks on rear legs.

Ergots

Ergots are located at the bottom of a horses fetlock

Grooming

CHESTNUTS

Soften the chestnuts with water or baby oil and then use your fingernails to peel off the outer layers.

Zebras and donkeys don't have chestnuts on their legs.