We just got 3 mallards about a week ago. All healthy up until last night. They are all 3 months old. Last night when we went to put them all up and feed them for the night I noticed one was missing from the yard.....so I opened the barn door and there he is upside down just laying there? Now about a month ago I found one of our pekin girls outside upside down and when I picked her back up onto her feet she stumbled around for a little bit then recovered, she's been fine ever since. So I picked this guy up thinking he just got knocked over and couldn't get back up. Well he kept flipping over, we put him in the pool and he kept flipping over in the pool too. His right side pretty much was worthless. We gave him a day or so to right himself, then my boyfriend ended his suffering tonight. I just couldn't keep him off his back :'( And I cried and cried. I just don't understand what happened to a healthy duck in just a couple hours? Also he would not eat, or drink anything as we left him with food and water all day and nothing was touched. Did I make the wrong call?