I've heard back from the Waterfowl Sanctuary - they are concerned that the duck may have Avian TB, so they can't take him as it is contagious to other birds.(?) I have to do some research on this to see what's what. He is still eating, drinking and getting along okay. I have continued some warm compresses, and let him puddle around in some warm water twice a day (as per suggestions here.) I am also giving him some azelastine hydrochloride ophthalmic drops, because that is all I have (they are supposed to work against allergic reactions/inflammation.) I am hoping to get a bit of a consultation on him tomorrow, so we'll see.