This morning I went out to let my chickens out (I have three at the moment well now two) and my eldest, only being about three or four months old, had white mucus draining from her vent and didn't run away from me like she usually does. She went and stood in one of the nesting boxes and didn't move when I petted her or picked her up so I knew something was very wrong. I took her up to the deck and tried to give her soggy food and water. She wouldn't stand on her own. I was feeling her crop and it was squishy but not big. She was puking up a brown colored liquid and after 45 minutes of holding her on a towel in my lap she died. She was completely fine last night, or she seemed to be fine, when I put her to bed. I am pretty devastated she died she is my first chicken to die. Anyways, now I am worried about the other two chickens who are eight weeks old. Does anyone have any idea what my first chicken had and do you think it is contagious? Or a way I can try and protect my other two? They are acting normal and their crops feel fine. Do I need to be worried or is there anything I can do?