Listeric septicemia with meningitis in a neonatal calf

A 9-days-old calf which had exhibited depression and difficulty to stand and walk was examined pathologically and bacteriologically. The primary pathological changes consisted of multifocal necrosis in several visceral organs and fibrinopurulent meningitis. The necrotic lesions were most frequently found in the liver, and accompanied with mononuclear cell infiltration and Gram-positive small bacilli. The organisms were also present in the foci of mononuclear cells at the central gray matter of the mesencephalon. Listeria monocytogenes was isolated from the brain and other organs of the whole body.