Duphamox Uses Duphamox is indicated in the treatment and control of infections caused by organisms sensitive to amoxicillin. Amoxicillin is a broad-spectrum semi-synthetic penicillin bactericidal in action. In vitro it is effective against a wide range of Gram-positive and Gram-negative bacteria which include: Actinomyces bovis, Actinobacillus equuli, Actinobacillus lignieresi, Bacillus anthracis, Bordetella bronchiseptica, Clostridium spp, Corynebacterium spp, Erysipelothrix rhusiopathiae, Escherichia coli, Fusiformis spp, Haemophilus spp, Moraxella spp, Pasteurella spp, Proteus mirabilis, Salmonella spp, Staphylococci and Streptococci (non-penicillinase producing) in cattle, sheep, pigs, dogs and cats.