My hen Beatrice (Buff Brahma, about a year and a half old) came back from the local fair and she seemed perfectly normal until a few days later. I noticed she wasn't running around the yard as fast as usual, and she didn't seem to have any interest in her daily activities. Just after I noticed that, I found her lying down and she couldn't get up. Other than that she looked perfectly normal and healthy, though a bit wobbly on her feet. Today I was taking a look at her legs and her vent, which had quite a large amount of poo around it. I also noticed a dead fly, as well as flies seemed very attracted to her. She keeps falling off the roosts, kepps falling over and can't seem to get to food. Do you know what this may be? Do I have to check for maggots, or is it just her leg?