Studies on correlations among parasitaemia and some hemolytic indices in two tropical diseases (theileriosis and anaplasmosis) in Fars province of Iran

This study was carried out in two observational clinical studies. Study 1 comprised 50 adult crossbred cattle naturally infected by Theileria annulata. Infected animals were divided into 4 subgroups with different parasitaemia (<1%, 1–3%, 3–5% and >5%). Study 2 comprised 20 adult crossbred cattle naturally infected by Anaplasma marginale. Infected animals were divided into 3 subgroups with different parasitaemia (<10%, 10–20% and 20–30%). In study 1, a significant negative correlation (P < 0.001) was observed between parasitaemia and superoxide dismutase (SOD). Positive correlations (P < 0.001) were observed between parasitaemia and lactate dehydrogenase (LDH) and mean corpuscular fragility (MCF). In study 2 positive correlations (P < 0.05) were observed among parasitaemia and MCF and LDH activity. SOD activity had a negative correlation with parasitaemia in cattle with parasitaemia lower than 10% but no significant correlation (P > 0.05) was observed between SOD activity and parasitaemia in cattle with 10–20 and 20–30% parasitaemia. In comparison of both studies we came to the conclusion that in theileriosis as the severity of disease increased the anaemia, MCF and LDH activity increased and SOD activity decreased at any parasitaemia, but in anaplasmosis the anaemia, MCF and LDH activity increased at any parasitaemia but SOD activity decreased only in early but not in advanced stages of disease.