Duckling problems

[BirdsBeesTrees]

And the shoes might help, too.

i can't find a good link for duck shoes.

 

[daniellespurr85]

You should make some shoes for him. I use painter's tape so it doesn't tear the skin when you take them off in 4 days or so.

How do I make them

 

[Aunt Angus]

How do I make them

This thread may help:
https://www.backyardchickens.com/threads/newly-hatched-duclking-leg-foot-problems.1015168/

 

[Crazy Maizie]

For that young of a duck, I would just feed a complete feed no mealworms especially since there are issues currently. You stated "duck mash", but not what type of feed.
I agree with supplementing niacin.
Could you post a full body pic? A pic next to the other duckling.
If not growing there is more than a niacin deficiency occurring.