Let us know how he is doing @myduckduckie also just in case you ever expect a toxin
https://www.backyardchickens.com/threads/flushes-for-aiding-in-toxin-removal.700526/
No dandelions are not harmful.
You may have some of these plants in your garden so i am sending this list even though it says north America
https://www.chickens.allotment-garden.org/poultry-illnesses-ailments/poisonous-plants-toxic-to-poultry-north-america/
on this one listed is blue-green...
Please keep us updated on him. Like @ruthhope mentioned keep him quiet for now is best stress can make things a lot worse. Even older ducks can be niacin deficient it can cause them to lose balance and eventually become lame and if not treated it can kill them. I have no idea if this is even a...
I think a watery soup made of his feed is a good idea he can drink it instead of eating ( soupy) since he’s drinking. I don’t know about a stroke it could be possible I’ve never heard of a duck having one. Also if you can get by some B Complex Vitamins to add to his drinking water or soup he...