Help! Mysterious, fluid filled mass, left chest in Roxie

[cfg]

3 days ago my 3 year old barred rock started sounding hoarse when clucking and on closer examination has developed a 6cm x 6cm mass that seems to be cystic and fluid filled. It is NOT her crop. I can shine a flashlight on the mass and it looks fluid filled (not solid, not pus-filled). ANy ideas what it might be? It is getting harder for her to eat and to breath, but she otherwise looks well. I have separated her from the other 6 chickens who all look well and are acting well.

I'll try and post a video on BC but here it is on youtube: http://www.youtube.com/watch?v=WuoAbTkbv8Y&feature=youtube_gdata_player


Any help would be greatly appreciated--I think we only have a couple of days before this mass gets too big and blocks her airway.

Thanks

(Again, it is NOT her crop so not sour crop)

 

[willowbranchfarm]

I don't know what it is or how to treat it but I would take her to a vet asap.