If your horse balks
If your horse balks, speak quietly to him. Horses like to be reassured just like people do. Remember, this is something new and possibly terrifying to him. If your repeated attempts to entice him into the used horse trailers fail, then you can proceed to some more persuasive methods. Two people can get behind the horse (make sure he is gentle if you try this method) and gently loop their arms around his buttocks grasping hands together and exerting slight pressure up against his back side. This will cause him to move forward, however one person still needs to be leading the horse. If you are by yourself, you can loop a rope around his hind quarters and essentially apply the same pressure by pulling on the end of the rope.