EN
Adult forms of Strongylus equinus, S. edentatus and S. vulgaris were used for preparing extracts in physiological salt solution as antigens. Rabbits were immunized with them and (weak) antibodies obtained, which could be discovered in the precipitation test. Because in this test as well as in the microprecipitation test with live larvae (obtained from eggs of parasites taken from the uterus) cross reactions appeared between all three immune sera and all aintigens, it was concluded that by means of the immunobiological methods used as above, it is not possible to determine the larva species of nematodes of the genus Strongylus.