(Pfizer Animal Health) Quartermaster is for intramammary use to reduce the frequency of existing infection and to prevent new infections with Staphylococcus aureus in dry cows. Quartermaster contains penicillin and dihydrostreptomycin in a peanut oil base. Each 10 ml tube of Quartermaster contains 1,000,000 units of procaine penicillin G micronized, and 1 gram of dihydrostreptomycin base, as dihydrostreptomycin sulfate. Instill the contents of one syringe into each quarter. Penicillin and dihydrostreptomycin.