Fusarium fungus Fusarium moniliforme produces mycotoxins called fumonisins. The important toxin is fumonisin B-1 which is a confirmed carcinogen. In horses, brain and liver are the organs affected. The most common lesion is the necrosis in the white matter which may occur as a result of low consumption of the toxin over a long time. Another condition is hepatitis which leads to degenerative liver disease (hepatoencephalopathy). Lesions of both
types may be present in the same animal. Fumonisins inhibit ceramide synthetase enzyme thereby blocking the biosynthesis of complex sphingolipids resulting in accumulation of sphinganine and sometimes sphingasine which act as cytotoxic agents, or lead to cell proliferation affecting a wide variety of cellular systems.