Visceral leishmaniasis (VL) is a parasitic disease can parasitize the reticuloendothelial system (RES) of the visceral organs; the amastigote of leishmania parasite invades the visceral organs spleen, liver and bone marrow. This study included experimental intraperitoneal inoculated of stray dogs with a live and infective Leishmania donovani promastigote forms produce the histopathological changes of internal organs of infected dogs. The average weight and length of liver and spleen of infected and control dogs were monitored and evaluate, The parasite disseminated to visceral organs liver and spleen, the characteristic histopathological infection was observed. Parasitism and the inflammatory reaction with parasites were noticed in liver and spleen organs, macrophages loaded with intracellular amastigotes were fond in tissue of all organs especially in spleen. The histopathological changes in visceral organs of infected animals may be explaining the experimental infection with L. donovani strain causes a canine visceral leishmaniasis. In conclusion, stray dogs play an essential role in the transmission of visceral leishmaniasis in Iraq; the histopathological changes in visceral organs depend on the virulence factors of strain of Leishmania parasite as well as associated with development of inflammatory cells that may be due to host response to the antigenic factors of the parasites.