Pinesap on horse?

["guest@endurance.net" <guest@endurance.net>]

Susan pynevalley@mindspring.com
Has anyone had experience with their horses rubbing against
pine trees and plastering themselves with the pinesap?  My
horses have stripped the bark from one of the pine trees 
possibly from rubbing and now have their necks, ears, manes and forelocks covered in the stuff.  I can't find anything to remove it, meanwhile it is removing all their hair.  Help please!