Parasitaemia and clinical manifestations in Trypanosoma brucei infected dogs.

Four dogs were infected with Trypanosoma brucei (Mkar strain) while another four were used as uninfected controls. Two of the dogs showed acute disease and died in the first wave of parasitaemia on days 7 and 8 post infection (PI) while the other two died from the sub-acute disease on days 24 and 28 PI corresponding to the second wave of parasitaemia. In the first wave of parasitaemia there was a sharp decrease in the packed cell volume, red blood cell, haemoglobin, total leucocytes, eosinophil, neutrophil and lymphocyte values, but during the period of low parasitaemia there was a slight recovery of the values of total leucocytes and lymphocytes although these and the other values showed a continuous decrease during the second wave of parasitaemia. In contrast, there was a consistent monocytosis in both acute and sub-acute diseases. The general picture was that of loss of condition, anaemia, leucopenia, monocytosis, ocular impairment, elevated temperature, pulse and respiratory rates, the difference between the acute and sub-acute diseases being in the degree of intensity. The degree of anaemia noted and the circulatory disturbances associated with the infection could have caused the death of all the infected dogs.