An experimentally Trypanosoma evansi infected dromedary (intravenous injection of 3 million parasites) was under investigation for 200 days. Already after 24 h, living trypanosomes were detected in the blood. On day 6, parasites reached a high density and the host showed first clinical signs. Several treatments with melarsomin on day 6 and in combination with quinapyramin on day 23, 68, 102 and 198 decreased the number of trypanosomes in the blood but did not eliminate the parasite indicating a drug resistant T. evansi strain. While throughout the observation period there was no signs of anaemia, the number of leucocytes increased shortly after infection and remained high later on. Antibodies indicating a positive surra infection appeared on day 20 and remained on a high level.
Key words: Dromedary, melarsomin, quinapyramin, Surra, Trypanosoma evansi