Hello, I got my Mallard ducklings from the feed store as I get most of my chicks and ducks. They are only a week old and 2 possibly 3 of my mallards are walking funny, limping, one duckling even walked on his knee (looked as if there legs were broken at the joint). On 2 of the ducklings (mallards) it was only one of the legs not both. What is the cause of this and have you ever seen this before ? I put them to sleep as soon as I noticed it because I knew they would not make it and I didn't want them to suffer. My White Crested ducklings did not have this issue ! Thank God. Thanks for the advice and help.