i got her at a feed store and she was a day old. There were no exposed intestines at all. She is happy, active, and very.....vocal. lol. I probably wouldn't have noticed it if she weren't damp from a wipe down.Recently a silkie breeder, that I know, had a chick hatch with part of its intestines protruding from the abdominal wall. Is it possible this may have happened with your chick and as the skin healed over the intestines it became a mass? The vent looking slit may have been part of the open abdomen at the time of hatch. If you did not have exposed intestines at the time of hatch, could this be something like a hernia?
Can chickens even get hernias? What do you do about them if they do?