Chest wall (crop?) is swollen, feels puffy and fluid filled, dying

[Summer98]

This is my third chicken to be dying with these same symptoms. I sent the second one to the university for a necropsy, but have not heard back from them in 2 1/2 weeks. Meanwhile, chicken #3 is now displaying the same symptoms and dying. I'm not sure what to do. I thought it was an impacted crop, but my vet said that would feel like a tennis ball near the sternum. My chickens have the entire chest wall feeling like a puffy, fluid filled balloon. If you press on their chest wall, they puke up mucous. They are very lethargic and their bodies seem to stiffen up. Last time I tried massaging the chest wall and nothing happened. This time I pressed on her chest wall and she puked a little. It feels so swollen and fluid filled compared to a normal chicken. They will not eat. They stand alone away from the flock, stare into space, and eventually lie down, puke and die. My vet is out for the rest of the day. Help!

 

[Summer98]

Now I'm wondering if it's sour crop. I don't understand how to treat it. Are we supposed to massage the contents of the crop upward i.e. vomiting or massage them downward through the chicken?