Avian botulism: geographic expansion of a historic disease

Avian botulism is a paralytic, often fatal disease of birds resulting from ingestion of toxin produced by the bacterium Clostridium botulinum. Waterfowl die-offs from the botulism are usually caused by type C toxin; sporadic die-offs among fish-eating birds, such as common loons (Gavia immer) and gulls, have been caused by type E toxin.