This time of year preds are moving around even in day light and a fox, Coyote, weasel etc Dog could pick your duck up and run off with it not leaving one feather behind. I'm so sorry to hear this happened but I believe this may explain what happened the pred could have been after your goose and the goose managed to get away but got wounded in the process, What ever it is knows you have food for the taking, I'd keep your flock penned up till you trap and kill what ever this is or I'm afraid you will lose more. If the wound is looking good and not healing to quickly remember it needs to drain then maybe not antibiotics but you are there and can see how it looks.No my duck is a Cayuga but have not found any signs of her at all. She was probably a good 7 or maybe 8 pounds. I'm not sure what could of happened. My gander is doing pretty good. He doesn't like being away from his friends and family though. He hears them outside and keeps calling out to him. He's very loud but I feel so bad for him at the same time. I have acv in his water right now too. I think I'm going to see if a mirror will help him. I have 4 ducklings in the house right now too but he seems to not care much about them. I do have them separate otherwise he would kill them. I just feel bad that he calls to his flock whenever he hears them. But other than that he is doing good. I have applied neosporin a few times to his wounds. His legs are warm but I'm not sure if that's because its warm inside or because it is infected. Both legs feel the same warmth though.