Both of my horses have insulin dysregulation and one of them, my mare, has had an episode of laminitis. Their insulin levels are currently controlled with diet and supplements. They are turned out in a dry lot with hay bags hung on the fence but they still reach through the board fence to eat grass outside of the lot. While I am sure that they do not consume large amounts of grass, I still limit their turn out time to 2-3 hours/day during the fall.