DISTRIBUTION:
A fungus that is one of the most prevalent moulds on harvested maize throughout the world. Maize is produced mainly in the North-West, the north-western, northern and eastern Free State, the Mpumalanga Highveld and the KwaZulu-Natal Midlands.
BOTANICAL DESCRIPTION:
General: A cosmopolitan fungus and one of the most common moulds on harvested maize worldwide. A cause of cob rot (kopvrot).
TOXIC PRINCIPLE:
• Fumonisin B1.
• Several other toxic metabolites were isolated, but not of significance for LEM.
• Fumonisin B1 is structurally similar to sphingosine, which is the backbone of
sphingolipids.
• Fumonisin inhibits sphingolipid synthesis.
SYNDROMES:
Leukoencephalomalacia (LEM).
SYSTEMS AFFECTED:
Central nervous and respiratory systems.
CLINICAL SIGNS:
• Leukoencephalomalacia (LEM) is a mycotoxicosis of horses following ingestion of maize contaminated by Fusarium verticillioides.
• The disease is characterized by focal liquefactive necrosis of the cerebral white matter.
• Horses exhibit a variety of nervous signs depending on where the lesions are in the cerebrum.
• The intoxication is invariably fatal.
• Lung oedema is seen in pigs.
NECROPSY:
Subcortical focal areas of liquefactive necrosis and haemorrhage.
