The immunity of cattle inoculated with Piroplasma mutans

Abstract

CONCLUSIONS: 1. The exposure of animals immune against redwater in the low veld proved that this immunity protected against the redwater of that veld. 2. Animals immune against heartwater were protected against that disease in the low veld. 3. Animals which were only immune against redwater contracted a Piroplasma mutans infection when exposed in the low veld. 4. All the animals which were not immune against Piroplasma mutans contracted this infection when exposed in the low veld, but none died. 5. Of the two control animals which were not immune against any of the ,diseases both died; Piroplasma mutans was present ~n both cases, but the deaths were due to heartwater, and in one case complicated with redwater. 6. All the exposed animals showed reactions, due either to heartwater or to some other agency, and this reaction, in the majority of cases, caused an increase in the number of Piroplasma mutans present in the blood. 7. The animals which were immune against heartwater, Piroplasma mutans, and Piroplasma bigeminum showed a slight Piroplasma mutans infection, and also a slight reaction.