It is hard to see it unless you open the chicken's beak. What is it? How can I treat it so it doesn't get worse. A few weeks ago it and another chicken looked like it might be gagging. They were opening their mouth wide like someting was in their crop. I thought they might have an impacted or sour crop. But the next day they seemed to be fine...then I saw this a few days later...the other one looks like he has this starting on his beak. Help!