In addition to putting your horse and his buddy to work in the roundpen, says Rieman, try working them while horseback in the pasture. If you're on foot, it's easy for your horse to get far enough away from the pressure and find release. It's a little more difficult when you've enlisted the help of a horseback friend.
Have a rider head to a neutral area of the pasture not too far from your horse and his buddy. Meanwhile, approach your horse on foot. If your horse runs from you and heads toward his pasture buddy, have the rider immediately head toward the horse applying pressure to both. The rider's object is to maintain pressure to keep both horses moving, not force them apart, until each willingly finds separation from the other, and shows a eagerness to be caught.
For more information, read this month's story, "5 Ways to Cure a Buddy- or Barn-Sour Horse." Randy Rieman can be contacted at (406) 925-2467.