A survey on the concentration of thyroid hormones and insulin hormone in cow with theilleriosis

Theilleriosis is a common protozoal bovine disease which causes to most economical losses. Knowledge about biochemical appearance in cattle affected by the disease is very important. The present study was conducted to evaluation of T4 and T3 hormone's serum levels and the rate of insulin in cattle affected by the disease and its comparison with healthy cattle. 37 affected cattle and 35 healthy cattle from large animal clinic of Islamic Azad University Tabriz Branch and some dairy farms of Tabriz. Blood samples from vena cava were obtained then thyroidal hormone's serum levels and the rate of insulin were measured by ELIZA method. T3 hormone serum levels in affected and healthy cattle were 52.02±4.47 and 46.54±4.82 ng/dl, respectively as well as T4 hormone serum levels in affected and healthy cattle were 5.92 ±1.06 and 5.36±0.74 μg/dl, respectively. The differences between two groups about both hormones was significant (p=0.000 and P=0.011, respectively). The mean of insulin serum concentration in affected group was less significantly compared with healthy group (6.83 ± 1.04 and 8.80 ±1.05 u/ml) (p= 0.000). In evaluating the correlation between thyroid and insulin hormones in affected group it was revealed that the correlation between T3 and insulin was not significant (p=0.077 and r= - 0.239) but the correlation between T4 and insulin hormones was significant (p= -0.280 and p= 0.046). The conclusion is that in Theilleriosis affected cattle the serum level of thyroidal hormones increase and insulin hormone decreases.