Botulism should always be considered when there is leg weakness. It is usually from eating decayed vegetation in compost, or from eating a decayed animal or fish carcass around flood prone areas, or when there is a dead animal that the owner doesn't know about. Maggots and mud from any of those things can cause it. Botulism usually kills right away, but it they live past 2 days, they will usually recover. The symptoms is botulism would be weakness in the legs progressing upward in the body to wings, then neck (they can't hold the neck up off the floor,) and paralysis of the 3rd eyelid, before death. Botulism isn't caused by mold--it is caused by a toxin formed anaerobically or without oxygen. Since you had the rooster with the gray eye, it more than likely is Mareks, although I couldn't ever diagnose that.
