Puffy Neck

[Mrsar2004]

My 3 week old duckling has developed a puffy neck, almost looks like a tumor on the side of his neck. I did a little research and called a local vet and he says its probably food stuck in his crawl?(sp) He said to look up what to do.... so I am asking the experts.... my friends on here.... Do you think that is what it is? IT's soft and it doesn't appear to bother him when I gently massage it. He seems to be eating normal and drinking normal. He is a miracle duck to say the least. He got shrink wrapped during birth but this little guy is a fighter. Any info would be greatly appreciated. What do I do to fix this?
Thanks so much! Amanda II took a few pics but you really couldn't tell because he is so fluffy. lol. so I didn't attach any.

 

[Eggcessive]

Could it be a leaking air sac which feels like air under the skin, which can happen after an injury? I will tag @Miss Lydia and @Isaac 0 since they know more about ducks. Do you have a picture?

 

[Mrsar2004]

I am not sure if you can tell but his neck appears to be crooked and swollen on the right side, down to his breast.

 

[Miss Lydia]

What a cutie. Could just be food in the crop area they can look swollen after they have eaten. especially since you say he is eating and drinking normal.