I noticed one of my chickens (she was VERY ill, and presumably "egg bound", a couple weeks ago - but recovered after several days) is wheezing, and I heard a cough. Then, another chicken had what looked to be "foam" on her eye. Then, another hen has one swollen waddle, and it feels hard, almost as though there were something (round like a "BB") inside it. And, another hen seems to be having a difficult time passing an egg! Could these be symptoms of something in particular? Thanks in advance!