I had tried using indomethacin (10 mg/kg) and diclofenac (25 mg/kg) as control in cotton pellet induced granuloma study, but during the experiment, the rats were died because of ulceration. I use male SD rat, 300-400 kg. I fasted the rat overnight and the treatment was given 1 hour before induction. I use DMSO and water respectively to dilute the drug. For DMSO, I make sure the percentage of DMSO given was 1%. Most of the study use indomethacin as the control, but in my case, all rats were died. May I know the correct method? Or do I need to use other drug as control?