Boots with hard shells that sit over the tendons on the back of the lower leg to provide maximal protection from interference with other legs or hard objects. On the front legs, the hard shell envelopes the back and both sides of the leg from just beneath the cannon bone, down to the fetlock joint, thereby covering the crucial tendons of the lower front leg. On the back legs, the shell of the tendon boots covers the back and both sides of the fetlock joint. The hard shells are held in place by soft straps that run over the front of the leg.