On Howrse how do you get the horse dung out of you'r inventory?

Just go to The Store and press, "Sell to Mrs. Hubert". Click on the dung and choose the amount you want to sell. You can get up to 10e per dung, depending on the cost. Probably the minimum you should ever get is 2e per dung. Hope that helps! My username on howrse is murrn.