My family and I started raising chickens last spring. We raised 5 Rhode Island Reds from chicks and added 4 more this year all seemed very healthy. About 1 week ago I found one of the older ones dead in the run, there was no signs of foul play. Yesterday I was checking on them after work and another chicken began to stumble, convulse, fell over and died. It looked like a little discharge left her mouth. Please help!