I have a group of 7 hens--they hatched in January. First eggs were early--April and were large. This week 4 out of 7 prolapsed, blood when I came home... 2 have died already. It's odd, last week I checked everyone's vent--nothing unusual and now this happened. Could I have added something to the feed to help this? It really threw me for a loop when 4 out of 7 have prolapsed, with the possibility that maybe all 7 will. And that 2 hanging on may die soon. Can anyone help me?