Evaluation of the erythrocytes and leucocyte alterations in cows infected with Theileria annulata

The percentages of anemia, parasitemia and leucocyte changes were investigated in bovine theileriosis in the Northwest of Iran. The hematological values in 91 cows with theileriosis were compared with 19 healthy ones. The disease was confirmed by the presence of parasites in the peripheral blood smear test. Five mLs of blood from the jugular vein was collected and mixed with EDTA. Hematological parameters and parasitemia were assessed by current laboratory methods. The mean for hematocrit (PCV), hemoglobin (Hb), total leucocytes counts (WBC) and erythrocyte count (RBCs) were 22.1%, 6.8 mg/dL, 7075/microL and 4x10**6/microL, respectively. Mean total protein, absolute lymphocyte, neutrophil, eosiniphil counts, MCV, MCH and MCHC were 6.4 g/dL, 3898, 2746, 136/microL, 55.5 fl, 16.7 Pg and 30.5 g/dL, respectively. Mean concentrations for PCV, Hb, RBCs, and MCHC were significantly (p is less than 0.05) lower and MCV was higher than the control group. To determine the severity of anemia in theileriosis, PCV was classified into cows without anemia (greater than 24%), mild (20-23.99%), moderate (12-19.99%) and severe anemia (less than 11.99%). Therefore, the frequency and percentage of infected cows were 44 (48.4%), 14 (15.3%), 23 (25.3%) and 10 cases (11%), respectively (p is less than 0.01). The percentages of parasitemia among 4 groups (1.23, 3.86, 9.64 and 34.2%, respectively) were also significantly (p is less than 0.01) different. Among the indices under study, mean RBCs and Hb showed significant differences (p is less than 0.01) in all types of anemia. The types of anemia were varied from normocytic hypochromic to macrocytic hypochromic. Negative correlations were found (p is less than 0.01) between parasitemia/PCV (r=-0.74), parasitemia/Hb (r=-0.64) and parasitemia/RBCs (r=-0.63). It is concluded that anemia would be the main clinical sign in theileriosis. Type of anemia varied based on the severity of the anemia. Hematocrit, Hb, RBCs MCV and MCHC are the main indices affected in theileriosis. The majority of the infected cows were affected by moderate anemia except for 11%, in that they showed severe anemia with 34.2% parasitemia. Thus, the assessment of RBCs indices will lead to the prognosis and appropriate treatment strategies.