1) What type of bird , age and weight. She was a white Leghorn (her name was Blondie) about a year and a half years old. Not sure of the weight 2) What is the behavior, exactly. She was lethargic but I thought it was because the cold weather - she did not do well last winter. But 4 days ago when I went to let them out in the morning she was already out and wet and miserable looking. I must have missed that she hadnt gone in the night before and there was a bad rain storm that night. Then I noticed blood dripping around her vent area. I brought her inside to isolate her from the rest. She had diarrhea and smelled really bad. She had two more bloody poops but the others were runny and clean of blood. I got her on Sulmet by Monday morning (day 2) and added some vitamins and electrolytes here and there. She seemed to be eating (some feed and yogurt and cottage cheese) and drinking. I bathed her this afternoon to clean her and get a better view of her vent and it was a little swollen but not bloody and it looked dirty like a poop was stuck but I couldn't clean it off. She passed after her bath. She was relaxed enough to lie down and then after an hour she was gone. 4) Are other birds exhibiting the same symptoms? Not yet they seem pretty robust and I dont notice any runny poops. 6) What happened, if anything that you know of, that may have caused the situation. She hasn't laid for a year even though she is of laying age - she laid regularly for a couple of months and then stopped laying last winter. There are small birds that keep getting into the run and sometimes the coop to steal the feed. I'm not sure what to do about that but I thought that may be how she got cocci - if that is what she had though she seems old for that. I wanted to see if I could get an idea of what it was so I can protect my others from it.