My bantam cochin is super sweet and I noticed that she is losing her tail feathers. I think it is the rooster getting at her. He just started breeding and I think he is a little slow. I picked her up to check for mites since it is starting to get warmer here we are starting our seasonal prevention. When I picked her up, no mites but there was this bulge ABOVE not below her vent. It was about the size of my thumb. There was a slit and it was oozing a little. I squeezed it and a hard white ball came out. Im not sure what it was/is. It didnt seem to hurt her. Does anyone have any idea of what it could be?