Serama's crop filled with air?

[MillersFarm]

I've got a 8/9 week old serama that isn't as perky as usual, So I went to look her over and notice a large air filled bump between her neck and wing, and i noticed that when I pushed on her crop it filled with more air. I don't think it's sour crop and it doesn't seem to be affecting her much, should I leave it be and keep an eye on it?

 

[SunHwaKwon]

How can you tell it filled with air?

How is it this morning? It should have emptied during the night.

 

[coach723]

I don't think that's the crop, it looks like a ruptured air sac. If it is not bothering her and not getting larger, I would just watch and it may resolve on it's own. If it continues to get larger, or she seems to have trouble breathing then you will need to release the air. It's done simply with a small sterilized sewing needle. Swab the area with some antiseptic, and make a small prick to release the air. Then put a dab of plain neosporin or triple antibiotic ointment on the prick once the air has released. Here is more info on air sacs:
https://www.beautyofbirds.com/firstaid.html#AirSacRupture
https://wagwalking.com/bird/condition/air-sac-rupture

 

[MillersFarm]

I assumed it was part of her crop since when I pressed on her crop it expanded. It's slightly smaller today but not by much. I'll just leave it be and watch her if it doesn't get bigger..