Heartwater in Nigeria. II. The isolation of Cowdria ruminantium from live and dead animals and the importance of routes of inoculation.

A study was carried out to determine which materials from animals dying or dead of heartwater could initiate the disease in susceptible goats, using the intravenous and subcutaneous routes. C. ruminantium was consistently isolated by intravenous injection of the whole blood or of lung macrophages and by subcutaneous injection of brain homogenate. In animals dead of heartwater, it appeared that isolation of the organism was achieved only when extensive post-mortem autolysis had not supervened. Experiments with blood fractions showed that leucocytic and plasma fractions of infective blood transmitted heartwater; the erythrocytic fraction consistently failed to induce an infection.