Botulism in chickens associated with elevated iron levels

Clostridium botulinum type C toxicosis was diagnosed by the mouse inoculati on test in two outbreaks of botulism in commercial broiler and roaster chic kens. 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 inve stigation. Elevated iron concentrations in the drinking water and/or feed m ay have presented a significant risk factor that may have resulted in intes tinal proliferation of C. botulinum and subsequent botulism.