Fig 1. Flow chart illustrating recruitment of equines to the treatment study.

Of the 254 animals which fulfilled clinical criteria for inclusion in the study, 162 subsequently proved PCR positive for at least one Trypanosoma sp. and were included in the treatment trial (n = 162). Animals that were PCR negative for all Trypanosoma sp. at the first examination were excluded from the treatment trial (n = 85). Adverse drug reactions were documented for the whole treated population (n = 254). Animals which fulfilled the clinical criteria for which PCR status was known (n = 247) were used to document the number of new or recrudescence of existing infections within treatment groups. Colours correspond to treatment group (blue = melarsomine, yellow = isometamidium, green = diminazene), exclusion (grey) or loss to follow up (dark grey) of animals.