I'm doing as much research as I can and finding out all kinds of stuff. It can e sores in their mouth, but all of them; I don't know..
It could be that the hay they're eating has some kind of fungus on it so it might be contaminated with this fungus. Not sure. I might start feeding them different bales of hay from a different stack. Could be that they have something blocking their esophagus, but all of them; seems not right for all of them to have a bone, stick or something lodged in their throat. Maybe coons and foxes contaminated the hay; is that even a possibility? They sure can't be teething at 3 years, can they? I know one of them is a yearling and yeah she might be teething. I'm not sure. I'm kind of thinking is the hay they're eating. Times are hard and hate to start giving them all shots for something they really might not need. What do you think?