You just have to be patient. I know it sucks, but it works. My horse got put away wet in the middle of the winter by the trainer (she was kept outside, and we don't use that trainer anymore) and she tied up. Then she got about the worst farrier job you can possibly give your horse. All that caused her to be lame from december untill march. The whole thing also made her joints forever sensitive. Just make sure you at least keep her walking, so she doesn't colic. Also, in order to prevent more problems from her being over weight, switch her to grass hay if she isn't already on it, and maybe feed her a little less of hay and fatty treats. When they get over weight, first, its a pain to get the pounds off, and they are more prone to further injury.