This study was conducted in College of Science, University of Mosul, it aims to identify the intestinal parasites that affect mice and their effect, this was done by collecting 37 mice, 22 of which were used as a control group, when a microscopic examination of the contents of the intestines of these animals is observed the presence of parasites Triohomonas Muris, during the period 2l10l2019 to 20l1l2020.
The number of mice infected with one parasite was 12 mice infected with two parasites was nine, while the rest were free of intestinal parasites.
With regard to the effect of these parasites on their hosts, an intestinal decrease was observed in the value of both haemoglobin and the volume of compressed blood cells in each of the infected mice compared to the controlled group. The infection, especially the double effect in the mice, caused an significant increase on the total number of white blood cells and an increase in the number of neutrophils and eosinophils and a significant decrease in numbers of lymphocytes cells at p>o.05