AniMed™ Epsom Salt (Magnesium Sulfate) is a barn essential, often used to draw out hoof abscesses and as a remedy for general soreness. Animed Label includes: Horses deficient in magnesium may have a poor tolerance to work and may be sensitive to environmental stress. Enclosed scoop measures approximately 1/3 oz and supplies approximately 926 mg magnesium. Directions: Horses less than 499 lbs body weight - 1/2 scoop daily; 500-899 lbs - 1 scoop daily; 900-1,099 lbs - 1-2 scoops daily; 1,100+ lbs - 2-3 scoops daily. Amount and frequency may be varied as necessary. Magnesium can be lost in sweat. For animals that sweat a lot, quantity could be increased 1-1/2 - 2 times recommended feeding amount. Feeding 4 or more times recommended amount may create a laxative effect.