Holly, those types of pastures (I have one!!) are/can be the worst type. I always thought because the pasture was short, it was safe, BUT, I have since learned that an overgrazed pasture can be worsen than a lush pasture. It all depends on why you have to worry about it. It is the starch/sugar that affects the IR/Cushings horses and causes them to founder. Stressed pastures are VERY high in that department. What I am trying to say, is it's not just overeating on lush pastures that are/can be the problem. I would much rather have my horses loose in their huge pasture, being horses, moving around and picking at the grass than to have one confined from the rest.