pole-evil

For this reason a front is used to the head-stall; it however then wears the horse’s head, and is the origin of what is called pole-evil; the bone of the nose is often worn through by the nose-band, forming abscesses _inside_ the nostrils.

Hints on Horsemanship, to a Nephew and Niece or, Common Sense and Common Errors in Common Riding George Greenwood 1837