I brought my chicken with a similar problem to the vet yesterday. I'm not sure if this will be useful to you, but I thought I would share. On Wed. morning I separated the chicken and put her on a water only diet. I figured if she was still pooping, then something in her crop was getting...
I have a 3 month old plymouth rock with the same problem. I'm so glad you posted pictures because I couldn't find anything like that anywhere else. My chicken has also had an enlarged crop for over a week and although it isn't getting super hard it seems like it just keeps growing. I am...