Swine cerebrospinal angiopathy and demyelination and malacia.

Abstract

In 15 pigs affected with cerebrospinal angiopathy accompanied by demyelination and malacia, the main symptoms were diarrhea and subsequent circling, spasms, sudden forward movements, ataxia, and inability to hold the head straight. Escherichia coli was isolated in a pure culture from the small intestine of pigs with diarrhea. The only gross change was a slight increase in cerebrospinal fluid. Histologic examination showed vascular lesions, demyelination, and malacia, most commonly located in the medulla oblongata, pons, and midbrain. The vascular lesions were degenerative and there were necrotic changes of the vessel walls and formation of periodic acid-Schiff positive perivascular eosinophilic droplets. Ultrastructurally, the swollen astrocytes around the vessels had many osmiophilic bodies in their cytoplasm with no limiting membrane. Demyelination and malacia, as well as vascular lesions, were considered to be the characteristic changes of cerebrospinal angiopathy. Our study suggests that E. coli may be a cause of cerebrospinal angiopathy.