The Collaborative International Dictionary of English v.0.48:

Crepance \Cre"pance\ (kr?"pans), Crepane \Cre"pane\ (kr?"p?n),
   n. [Cf. L. crepare to crack.] (Far.)
   An injury in a horse's leg, caused by the shoe of one hind
   foot striking and cutting the other leg. It sometimes forms
   an ulcer.
   [1913 Webster]