Actinobacillosis in pigs seems to be relatively rare and when it does occur, it usually manifests itself as acute septicaemia during the first weeks of life (Zimmermann 1965). Polyarthritis, pneumonia and heart lesions as well as petechial haemorrhages in skin, viscera and kidneys are also frequently found (MacDonald et al. 1976, Jones & Simmons 1971). Both Actinobacillus suis and Actinobacillus equuli have been isolated from such cases (Pedersen 1977).