The effect of trypanocidal drug treatment on the haematological changes in Trypanosoma brucei brucei infected splenectomised dogs.

Twenty adult mongrel dogs of both sexes were used. Ten of the dogs were splenectomised and the remaining dogs were left intact. Five dogs each from the splenectomised and non-splenectomised (intact) animals were infected intravenously with Trypanosoma brucei brucei while the rest served as uninfected controls. All the infected dogs developed trypanosomosis between Days 4 and 8 postinfection. The packed cell volume, haemoglobin concentration, total red blood cell count and white blood cell count decreased progressively indicating anaemia and leucopenia. The absolute reticulocyte counts were increased. Splenectomy enhanced fever, reticulocytosis and parasitaemia but delayed the onset of anaemia and leucopenia. It also shortened the prepatent period of the infection. The treatment of the infected dogs with diminazene aceturate (Berenil at the dose rate of 7.0 mg kg-1 body weight on Day 21 postinfection cleared the parasites in blood within 24 h and resulted in complete reversal of all the haematological aberrations observed. Splenectomy did not enhance or inhibit the recovery rate in the animals after treatment.