I'm sorry to hear about your duck. I can't be much help but one of our ducks has had a few of the same symptoms this past week (green poop, not eating). I don't know/ doubt that both our ducks are having the same issue but I have a vet appt. this evening and will post whatever the vet finds out...maybe it would help you as well.
https://www.backyardchickens.com/th...ick-what-am-i-missing-also-poop-pics.1324585/
https://www.backyardchickens.com/th...ick-what-am-i-missing-also-poop-pics.1324585/
