My Syrian hamster Edgar has just died randomly tonight. He was perfectly healthy and playing around yesterday. He was fine yesterday and early this morning, but when I came home this evening he was sleeping in a spot he has never slepted before. He was very limp and cold but still breathing. I held him on a heating pad on low and he would move parts of his body. He then seemed to be almost gagging or gasping for breath and shaking. He then died after about an hour and a half of holding him. Does anyone know what may have happened to him? I have had him less than a month and he is no older than 4 months old. Attached is a photo taken last week.