My mom has a spotted saddle horse that wont lunge to the right. He does great to the left. When you get on his right side and start to lunge he will take a few steps forward then spin is rear end around to face you. We have been working on desensitizing a lot on that side since before you could hardly walk in front of him to get on his right. We have never seen him lunged that way by anyone for what it's worth. Any ideas?