Vomiting duckling

[Indianrunner123]

I have an Indian runner duckling who will be 4 weeks old on Sunday. Everytime i feed him he vomits watery stuff up afterwards. Tonight was different however. He seemed to vomit up alot more and then he began wheezing and was not at himself. He seems to be recovering now.
He aways does this and his parent also choke on their meal but they get it down.

Is this just a problem with Indian runners or is it more serious?

 

[Pyxis]

Are you feeding him free choice (as in, he always has access to food)? A growing duckling needs access to food at all times because they need to eat so much to sustain their growth. If you don't feed him free choice, then when he does get access to food he's going to wolf it down as fast as he can, also taking drinks of water because ducks need to do that when they eat, overfill his crop, and end up 'vomiting' like you are describing. This puts him at risk of aspirating the liquid into his lungs and developing aspiration pneumonia, which is fatal if not treated.

Also, what are you feeding him?