In the present study, serum biochemical constituents were investigated in three groups of calves naturally infected with Onchocerca gutturosa. They were medicated with Ivermectin, Chloroquine or Artemether. The results showed that administration of any of the aforementioned drugs did not significantly (P>0.05) affect liver or kidney functions of the treated calves and the obtained values of total protein, albumin, globulins, urea, uric acid and creatinine were found to be within the normal level. However, significant increases in serum globulins, urea, and uric acid post-treatment were observed to be associated with reduction in dermal microfilariae count. Furthermore, these metabolites showed sustainable levels following repeated doses with these drugs and prolonged clearance of skin microfilaria (mf) confirming the observation that they are due to death of microfilariae and its role in production of immunoglobulin complexes that may cause transient changes in functional glomeruli.