Hi-
I am a pretty new chicken owner but I just went through this... adopted a 1.5 y.o. hen who had an impacted crop. After a week+ of care, she is fine now. I will try to tell you what I know:
1. A normal crop feels different at different times, depending on when the chicken last ate and what it ate. Sometimes it feels full of seeds, grass, whatever. if you go feel the crop late at night when they haven't eaten in a while, it will be empty, just folds of skin at the breast. I think a normal empty crop feels rather tight, whereas the crop of my sick bird, after it finally emptied, was very loose and baggy for a while until it healed.
2. Abnormal crop- As above, plus another type of abnormal crop is when it's filled with a gassy, quishy, liquidy substance. often called "
Sour crop" (see Karri's post from yesterday). This can occur on its own, but our hen with the impacted crop got it the day after we got her impacted crop emptied. You can read about that in the post I linked below. My girl's
impacted crop felt like a lump of modeling clay: solid but pliable. I believe it can also feel rock-hard, perhaps when it's gone on longer?
3. Other symptoms might include weight loss, since the bird isn't absorbing food (ours had sudden drastic weight loss) and less or no poop, or poop that is green due to not absorbing food. Sour crop can cause vomiting.
4. I monitored the crop over a couple of days and ascertained that it wasn't emtying on its own, and saw she was getting very thin. I felt I needed to intervene. Here's the thread about my experience.
https://www.backyardchickens.com/forum/viewtopic.php?id=21498 A summary of the treatment we used is on page 5. It was not difficult but did entail bringing her inside and spending hours every day caring for her.
karri's thread on sour crop is here:
https://www.backyardchickens.com/forum/viewtopic.php?id=22357 it follows the whole ordeal so read though it for all the info.
5. I don't know when it's an emergency. I guess if you can't get it emtied using just massage and oil as we did. If you have access to (and can afford) an avian vet, it's probably best to take them in, as I gather that some of the syptoms can indicate an underlying problem as well. If you search the archives you will find threads about people doing crop surgery on their birds to emty the impaction. I am ever so glad I did not have to do that!!!
Good luck,
Stacey