She died this morning after I found her lying in the corner in the coop. She was a RIR, about 9 months old. I do have a heated water dish in the coop which was plugged in to an extension cord that runs outside the coop. She was lying right next to the extension cord. I examined the cord, it looked like it had been nibbled on, but there were no wires or anything actually exposed. When I found her this morning, she was still alive but unable to stand. I moved her to quarantine immediately. While I was holding her she would move her head around and around in circles, but it looked weird - like she was moving her head at odd angles. Hard to explain. No nasal congestion, her eyes were clear. No obvious trauma to her body. She was getting layer feed and she also had access to hay in the pony's pen. She was a favorite and we'll miss her.