From a series of experimental studies with pigs (12-16 kg), either pulmonary edema or liver failure emerged as a distinct pathogenetic expression of fumonisin B1 (FB1) toxicosis. The primary determinant as to which pathogenetic consequence developed was the quantity (dose) of the mycotoxin fed or intubated per kilogram of body weight per day. Pigs intubated with a minimum of 16 mg FB1/kg/day developed severe interlobular edema with or without hydrothorax and variably severe pulmonary edema. Pigs intubated with < 16 mg FB1/kg/day or pigs fed diets containing 200 mg FB1/kg of feed developed marked icterus and hepatocellular necrosis. The spectrum of degrees of severity of pulmonary edema observed in the experimental pigs allowed rational speculation regarding evolution of the pathologic changes.