Chemotherapy is the main approach of trypanosomal control. This study aims to examine the
efficiency of the commonly used antitrypanosomal drug Diminazene aceturate (DIMA) or
Berenil against Trypanosoma evansi, in vivo. The criteria used for assessment of the
antitrypanosomal effect included the examination of the host blood as well as monitoring the
morphological changes inT. evansi as seen by SEM. Sixty Swiss albino mice, groups of fifteen,
were employed. These animals were divided into four groups; non-infected and non-treated
control, infected with locally isolated T. evansi strains receiving no treatment, infected-treated
with DIMA (20mg/kg)sacrificed after 4 hand 8 h post treatment, respectively.SEM
demonstrated that infection with T. evansi produced several alterations in RBCs structure
including the appearance of microspherocytes, schistocytosis, aggregation, doughnut-cell
formation, keratocytosis and increment of the biconcave appearance of cell diskocytes. In
addition, RBCs were constantly observed to adhere firmly to trypanosomes. After 4 and 8h of
DIMA treatment, the cells aggregated were dispersed and the biconcave disk shapes of RBCs
create large and stable contact area between adjacent cells.These results also indicated that, in
comparison to the untreated group that display normal T. evansimorphology and surface
topology, parasite exposed to DIMA for 4h revealed a number of morphological alterations in
the body shape including rounding of the parasite's body and in several instances, shortening of
the flagellum. Following 8h of treatment, drastic morphological changes were observed with
torsion and shortening of the body, sometimes with the aspect of a tadpole-shape and a
pronounced reduction in the size of the parasite, while the region of the free flagellum was
preserved.This study demonstrates the potential of DIMA in vivo in the treatment of
trypanosomiasis.