Evaluation of Norfloxacin Acute Toxicity in Five Day old Broiler Chicken

Abstract

Background: Norfloxacin is a second generation fluoroquinolone, used widely against sensitive organisms. After the withdrawal of enrofloxacin by the U.S. FDA for its use in poultry, the importance of Norfloxacin is getting increased and already some veterinary formulations were introduced by pharmaceutical companies in the market. The present study was undertaken to evaluate the acute toxicity of Norfloxacin IP, a member of fluoroquinolone in five day old broiler chicken.
Materials and Methods: Healthy 60 COBB broiler a day old chicks, with an average body weight of 45±5g were acclimatized to the laboratory condition for five days. Six groups; each group consisting 10 experimental birds were used for determining LD₅₀ safety value. Clinical observations were made. The tissue samples from concerned organs of all the birds were collected for histopathological study.
Findings: The maximum dose of Norfloxacin, where no mortality occurred was 1.4 g /kg. The dose at which 100 percent mortality observed was calculated to be 1.8 g/kg /body weight. The  clinical signs of toxicity observed before death were dullness, excitability, and drowsiness, circling, oozing of fluid from mouth and gasping for breath with beaks wide open. The calculated LD₅₀ value for Norfloxacin was found to be 1.55 g/kg for 24 h observation period. The histopathological findings observed in concerned organs were: hemorrhage, congestion and tubular epithelium degeneration and necrosis in kidney, Hemorrhage, edema and infiltration of few inflammatory cells in heart. Congestion of vessels and dilatation of sinusoidal space were observed. Perivascular hepatocytes were degenerated with infiltration of few inflammatory cells on liver and sever lymphocytolysis in spleen.
Conclusion: Norfloxacin can be classified as a moderately toxic drug according to Global Harmonization System (GHS) for classification of toxic compounds as per given protocol.