Muscovy drake can't walk help me!!!

[Muscovies]

My muscovy drake walks with a limp and can't walk I need help please!!!!

 

[chickenzoo]

We would need more info to help.
How old is he?
What do you feed?
how long has he been doing it?
What part of the leg?
What does his poo look like?
Is he eating and drinking?
Could he have gotten into moldy feed or something?