The pattern of damage occurs because the toxin affects nerves that are firing more often. For example, the inhibition of the release of Acetylcholine from motor neurons results in a loss of muscle function and paralysis. In poultry and wild birds, flaccid paralysis is usually seen in the legs, wings, neck (twisting) and eyelids. Broiler chickens with the toxicoinfectious form may also have diarrhea with excess urates and respiratory problems.
Healthy birds, affected birds, and dead birds in various stages of decay are commonly found in the same area.
Consequently, birds are unable to use their wings and legs normally or control the third eyelid, neck muscles, and other muscles. Birds with paralyzed neck muscles cannot hold their heads up and often drown. Death can also result from water deprivation, electrolyte imbalance, respiratory failure, or predation.
Copied and pasted from symptoms of Avian Butolism.