A case of an infant foal death was examined. The foal died 8 h after physiological parturition with symptoms of anorexia, listnessness and fever. Numerous extravasations in heart and spleen, congestion of lungs and cell degeneration of kidneys and liver was found during autopsy. A profuse growth of Actinobacillus equuli was obtained from internal organs of died foal. Clinical sings and anatomopathological lesions and results of bacteriologic examinations suggest a septicaemic nature of the disease.