I have a BLRW splash hen that started acting a little off 2 day's ago. She was just standing around and she wouldn't even come for corn so I knew she wasn't feeling well. I brought her in the house and put her in a dog crate. Started giving here vitamins and electrolyts. She showed no signs of illness. No runny nose, no sneezing, no coughing, nothing. I checked her vent and her crop and both seemed fine to me. Well I went to check on her this morning and she died sometime during the night. Any idea what could kill a chicken so quick? I am at a total loss and I am worried about my other BLRW and the silkies that are in a pen right beside there's.