I have 16 pullets, 6 ISAs. I noticed one moving her head in a circle. When I looked at her straight on, I could tell that something about her chest wasn't right. One whole side of her chest has a very large (golf ball size/shape) lump on it. I carefully picked her up to bring her outside to spend some "one-on-one" time with her. She seemed to walk a little slowly, but otherwise ok. She ate grass and did everything else fine. Back inside she flew up onto the roof (about 2 1/2 foot off the ground). She flew down fine, if maybe a little carefully. Later in the day I saw her holding both of her wings out and kind of panting. She didn't have the rapid throat movement though. It was humid today, but none of the other chickens was doing it. The lump seems to be semi-hard. It's not like a rock, but not soft like skin either. Someone please help me!!