SPINAL-CORD DEGENERATION IN ADULT DAIRY-COWS ASSOCIATED WITH THE FEEDING OF SORGHUM BEER RESIDUES

A neurological syndrome in a herd of Friesland cows (n=100) on a diet including sorghum beer residues is described. Over a period of 8 month s, 76 cows developed weakness of the hindquarters, progressively worse ning ataxia and, eventually, paralysis and permanent recumbency. The c ourse of the disease varied from 2 to 8 weeks. The lesions were signif icant in the 2 cows necropsied and included extensive, bilaterally sym metrical dilation of myelin sheaths, axonal swelling and loss with Wal lerian degeneration, and depletion of myelin in both ascending and des cending tracts at all levels of the spinal cord. Focal neuronal degene ration in the spinal cord grey matter and dorsal root ganglia, and foc al loss of axons and ovoid formation in the spinal nerve roots and isc hiatic nerves were also evident. The pathogenesis of the spinal lesion s appears to involve a primary axonopathy with secondary myelin loss. The epidemiology, clinical signs and pathology suggest that the diseas e was associated with the fungus Aspergillus clavatus.