| [serological study of the occurrence of l. hardjo in sheep in the netherlands]. | sheep (3918) from 137 farms in the regions of north-, west- and mid-netherlands and gelderland were serologically investigated for the presence of antibodies against leptospira hardjo. antibodies were detected in 3.3% of the sheep. there were large regional differences with respect to both the percentage of positive sheep and the percentage of positive flocks. all sera from sheep in gelderland were negative. in west- en mid-netherlands there were 0.9 and 6.5% positive sera, respectively, and 19. ... | 1993 | 8346509 |