Baby Muscovy duck not healthy?

[IChickenGirl]

Ive had this Muscovy duck for around 4 weeks now. Normally, he is a screamer and loves to run around and have fun. But today, i noticed he was not peeping, only at the slightest, and he is not walking. Ive been giving him vitamin water and bread, but he is not eating/drinking anything.
Help?

 

[Miss Lydia]

Ive had this Muscovy duck for around 4 weeks now. Normally, he is a screamer and loves to run around and have fun. But today, i noticed he was not peeping, only at the slightest, and he is not walking. Ive been giving him vitamin water and bread, but he is not eating/drinking anything.
Help?

Why bread? do you feed him duck grower or chicken grower? he maybe deficient in very important nutrient . Tell us more about him, what you feed, how he is kept. are there anymore ducklings beside him? and