I do not supplement with niacin under the assumption they are getting enough from their feed (in her case Scratch & Peck Organic Starter)
Thanks for your suggestions!
I have a Welsh Harlequin duckling that is not doing well. She(?) acts like she feels ok but she is not growing and she has an area around her eyes that is missing down and just looks unhealthy. (See photos)
I tried frequent assisted head dunkings but it did not help.
All the other 40 ducks...