Acute Trypanosoma vivax infection in dairy cattle in Coast Province, Kenya.

In an outbreak of a fatal haemorrhagic disease in exotic dairy cattle (Friesian, Guernsey, Ayrshire and Jersey) on 2 farms in the Coast Province of Kenya, and investigation was conducted to establish the aetiological agent involved. Blood and lymph node smears made from clinically sick cattle indicated infection with Trypanosoma vivax. Five calves were then experimentally inoculated with heparinised blood from cows naturally infected with T. vivax. All calves had a high T. vivax parasitemia, marked depression and fever; 2 developed blood-tinged diarrhoea 6 and 7 days were treated with isometamidium chloride while others were left untreated. Cases of abortions, bloody diarrhoea and deaths dropped markedly in the treated animals whereas they continued to occur in the untreated animal.