Clinical and pathological aspects of an outbreak of equine leukoencephalomalacia in Spain.

In 1988 an outbreak of leukoencephalomalacia was diagnosed in equids that had eaten corn with a pinkish fungal growth. The fungus was then identified as Fusarium moniliforme. The main symptoms observed appeared acutely and were overexcitement, blindness, incoordination, facial paralysis and death within 24 h. The main pathological changes were restricted to the central nervous system. Macroscopically they consisted of hyperemia and haemorrhages, the consistency was friable and the gyri were somewhat flattened. Microscopically, the lesions were profuse and had extensive haemorrhages, and numerous neurons appeared in different stages of degeneration and necrosis, with satellitosis and neuronophagia. Perivascular cuffs formed by macrophages, plasma cells and lymphocytes were also observed. These lesions were present in both brain and cerebellum, with a marked oedema and massive necrosis of the Purkinje cell layer of the latter.