Characterization of experimentally induced equine leukoencephalomalacia (ELEM) in ponies (Equus caballus): preliminary report.

An isolate of Fusarium moniliforme (M-1225 Cairo #1) was cultured on autoclaved corn and fed daily to 5 ponies at a rate of 2.5 g corn/kg body wt. One pony developed clinical signs of toxicity after 28 days and was sacrificed. The remaining 4 ponies developed no clinical sign of toxicity even after extended exposure. Hematology, serum chemistry, cerebrospinal fluid (CSF), and liver and brain pathology were evaluated as possible diagnostic and prognostic indicators. Hematology was not informative. Aspartate aminotransferase and gamma-glutamyltranspeptidase activities were elevated only in the clinically positive pony. CSF was most informative. Elevated myelin basic protein levels (greater than 14 ng/ml; normal less than 2.0 ng/ml) and cytologic changes consistent with chronic inflammation were observed in the clinically positive pony. Chronic inflammation was also seen in one clinically normal pony. Cytoplasmic vacuolation and clumping were observed in the hepatocytes of all ponies. Brain pathology was consistent with ELEM in the clinically positive pony.