Botulism in chickens associated with elevated iron levels.

Clostridium botulinum type C toxicosis was diagnosed by the mouse inoculation test in two outbreaks of botulism in commercial broiler and roaster chickens. One case involved 7-wk-old commercial roaster chickens, and the other involved 15-day-old commercial broiler chickens. A definitive point source for preformed C. botulinum exotoxin was not identified in either case investigation. Elevated iron concentrations in the drinking water and/or feed may have presented a significant risk factor that may have resulted in intestinal proliferation of C. botulinum and subsequent botulism.