Phenylbutazone Powder For the relief of inflammatory conditions with the musculoskeletal system in horses. Citrus flavored powder. One gram scoop included. Each 10 grams of powder (1 level scoop) contain 1 gram of phenylbutazone. The scoop equal one gram.Dosage is recommended at 1-2 scoops per 500 lbs. body weight daily with feed. Phenylbutazone. Brand may vary.