I bought 4 pekin ducklings a little over a week ago and everything was going great until 3 nights ago we noticed one of the ducklings couldn't walk. He/She is dragging its legs, basically walking on his/her elbows. We were given chicken starter to feed them which has 15 % protein. We've tried calling the place we got them and a couple vets but no one will help. I have read other posts with similar problems and polyvisol was recommended....any thoughts? Is the food wrong? They have a nice home with bedding water and food. I don't want to give up on the little guy. Please HELP.