Tilena
In the Brooder
If I were you I would not actually wrap or bandage your duck. It's a bruise my ducks have had that before and the others were picking at it so I got this in the picture and they stopped picking at her. I used a paper towel to apply it. It's not harmful to the other ducks if they get it in their mouth. If they get it in their mouth they will not like they taste and stop picking at her. I would definitely put it on it looks like their may be a little bleeding and that will help it heal faster to. It will leave her purple for a little while but will eventually go away.
Best of luck!
Best of luck!