The aim of the present study was to evaluate the immunomodulatory effects of orally administered oxytetracycline HCl (OTC) of 75 mg/kg body weight for 10 days on the immune response in sea bream (Sparus aurata L. 1758) using the nitro blue tetrazolium (NBT) reduction test and erythrocyte and leucocyte counts. Administration of 75 mg/kg OTC for 10 days enhanced the non-specific immune response, and increased NBT (+) cell, total erythrocyte and leucocyte numbers in sea bream at 23 ± 1 ºC. The effect of OTC on the immune system lasted around 21 days after ceasing the administration and the parameters evaluated then returned to normal levels.

The aim of the present study was to evaluate the immunomodulatory effects of orally administered oxytetracycline HCl (OTC) of 75 mg/kg body weight for 10 days on the immune response in sea bream (Sparus aurata L. 1758) using the nitro blue tetrazolium (NBT) reduction test and erythrocyte and leucocyte counts. Administration of 75 mg/kg OTC for 10 days enhanced the non-specific immune response, and increased NBT (+) cell, total erythrocyte and leucocyte numbers in sea bream at 23 ± 1 ºC. The effect of OTC on the immune system lasted around 21 days after ceasing the administration and the parameters evaluated then returned to normal levels.