We devote this study to clarify the pathological alterations occurring in naturally infected dromedary she-camels with T. evansi causing abortion and stillbirth using parasitological techniques for accurate and rapid detection of T. evansi on both fields and experimental levels. Also, to investigate and insure histopathological alterations in the experimentally infected
pregnant female mice with T. evansi detected in blood of naturally infected she-camels. 220 she- camels (Camelus dormadarius) belonged to different localities in Wahat Baharia and Mattroh governorates (suspected cases, clinically diseased cases, aborted cases and healthy animals for comparison) were examined by direct microscopic examination of wet blood smear and Giemsa stained of thin blood smears. Out of them, 92 animals (51.39%) were
positive for T. evansi infection. The suspected cases of abortions in the infected dams recorded from fifth to tenth month of gestation were 52 (34.78%) cases. The clinical signs of trypanosomiasis in the study areas included intermittent fever (39.5 - 41°C), weakness and emaciation with pale mucous membrane and dry scruffy coat. The eyes appeared dull and half
closed with considerable amounts of tears, in addition to the animal stand with his head raised toward the sun. Histopathological examinations revealed degenerative changes and necrosis in placentas and uteri of aborted dams. Congestion and necrosis were detected in liver. Hyperplasia of spleen lymphoid follicles of aborted and stillborn feta was evident. The experimentally inoculated pregnant female mice with the blood of the naturally infected she-camels were conducted and the uterus, liver and spleen of the aborted dead female mice showed the same lesions as in aborted she-camels, feta and stillborns