B ackground: Flunixin meglumine is a non-steroidal anti-inflammatory drug used in the treatment of several conditions in veterinary medicine. Objective: The study was aimed to investigate the analgesic and anti-inflammatory effects of flunixin meglumine in chicks. Methods: The up and down method was used to assess the median lethal dose (LD 50 ) and effective median analgesic dose (ED 50 ) of flunixin meglumine administered intraperitoneally (i.p.) and orally (p.o.) in chicks. From the obtained values we determined the drug safety indices. Electric stimulation method was used to determination the dose-dependent analgesic effect of flunixin meglumine in chicks. Analgesic and anti-inflammatory effects were dignified via the formalin test. Results: The median lethal doses (LD 50 ) of flunixin were 143.24mg/ kg intraperitoneally and 170.77mg/kg orally. The effective median analgesic doses (ED 50 ) of flunixin meglumine in chicks were 9.34 mg/kg and 11.75 mg/kg for intraperitoneally and orally respectively. The Therapeutic Index, Standard Safety Margin and Therapeutic Ratio of flunixin through intraperitoneal and oral route were (15.35 , 14.53), (0.15 , 0.14) and ( 5.11 , 4.84) respectively. The dose-dependent analgesic effect of flunixin meglumine at 9 mg/kg, 18 mg/kg ip and 12 mg/kg, 24 mg/kg p.o started at 15 min after treatment and lasted over 120 min of treatment. The analgesic effect peak of flunixin meglumine through intraperitoneal and oral routes was 30 minutes after treatment. In formalin test, flunixin meglumine caused a significant rise in the latency to lift right foot in comparison with the control value, along with a significant decline in foot lifting frequency. A substantial decrease in foot thickness compared to control value has been demonstrated by the anti-inflammatory effects of flunixin meglumine. Conclusion:These results shows that the flunixin has analgesic and anti-inflammatory effects and form the backbone for further pharmacological studies as well as the medication could be safely administered to chicken.

Objective: The aim of the study was to investigate the concentration of flunixin in the plasma of chicks to determine the pharmacokinetic parameters. Methods: A randomized controlled study was performed on forty five clinically healthy ross chicks of seven days old, chicks were administered into the peritoneum with a single dose of flunixin 18mg /kg b.wt, following injection of the drug, blood samples were collected at 0, 0.08, 0.15, 0.5, 1, 2, 4, 8, 24 h (five chicks per time) from the jugular vein after decapitation. Then the plasma was obtained, the concentrations of flunixin in plasma samples were determined utilizing Enzyme-Linked Immunosorbent Assay, the pharmacokinetic parameters were calculated by the PKSolver program. Time vs. concentration curve for flunixin was obtained from the program. The pharmacokinetic parameters were determined with non-compartmental models. Results: The concentration of flunixin in the plasma of chicks treated with flunixin by injection into the peritoneum at a dose (18 mg/kg) were 111.