Newly hatched chick has a clear swelling between its legs - almost as long and wide as your thumb. Made it walk with one leg splayed but was eating. Poop was a bright green. Next day didn't look good. I popped the swelling and fluid about the colour of diluted iodine came out - no smell. Seemed to help as breathing had become gasping . Hours later it had swollen back up so poked it again. Helped but died an hour or so later. Any ideas what it could have been or caused by?