Influence of Dicrocoelium danderiticum obtained from the liver samples on hematological profile of slaughtered cattle in Semnan, Iran

This study was conducted to determine the eventual changes of hematological parameters caused by Dicrocoelium danderiticum during the subclinical phase of the disease in asymptomatic cattle from Semnan, Iran. For this purpose, blood samples were collected from 50 healthy cattle during necroscopic examination of the liver at slaughterhouse. Samples for hematological analysis were taken from the jugular vein into EDTA-K2 containing vacutainer tubes and transported at +4 °C to the laboratory of the Veterinary Faculty in Semnan. Of the total 50 liver samples obtained from cattle, adult flukes in the bile ducts were observed in 40 % of samples (20 of liver), and the 60 % remaining (30 of liver) were negative. Erythrogram and leukogram were determined on blood samples from 20 infected and 30 uninfected cattle. Hematological analysis of infected cattle revealed the increased levels of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), lymphocytes, and eosinophils when compared to the uninfected cattle (P < 0.05). A significant reduction in RBC counts was observed in infected compared to non-infected cattle (P < 0.05). There were no significant changes in the mean values of PCV, hemoglobin, MCHC, and the rest of the differential leukocyte counts. According to the results, the anemia observed in cattle infected with D. dandriticum is a macrocytic, normochromic anemia, which indicates that anemia is strongly regenerative. The most important cause of this type of anemia may be attributed to the nature of subclinical infection. Lymphocytosis may be due to the inflammatory process caused by this infection and eosinophilia represents a parasitic infection.