The study was conducted on 10 days old, broiler chicks, the chicks were orally administered enrofloxacin 10% in a dose of 10 mg/kg body weight for five successive days. Entric contents samples were taken, diluted and inoculated in ROGOSA media, directely after drug withholding and every week after, for five weeks. Body weight also was recorded weekly. The
results showed that, enrofloxacin 10% in a dose of 10 mg/kg. body weight orally administered for five days, had a temporary inhibitory effects on the entric lactobacillus of broiler chicken. The lactobacillus of enteric contents returned back to its normal pattern one week after with-holding of the drug. It was concluded that, enrofloxacin had insignificant effects on the body weight in broiler chickens.