I have a flock of 7 peckin mature ducks and 7, 1-year old chickens. They free range and we have a pond. A night we put up in an enclosure. One of my female ducks didn’t come in Tuesday evening and was found on her back Wednesday morning. She was unable to quack or orient herself to stand / walk. I have given her b12 and some niacin. This was not a quick onset, she had been a bit wobbly but had been staying with the flock.I have kept her inside in a box and she isn’t eating much. Head wobbles and seems her equilibrium is off. Watery poop with some green. I would appreciate any help!