Use of a compound having the formula (I) in the manufacture of a medicament for the prevention or treatment of a diseased caused by oral bacterial in an animal Formula (I)； wherein R1 is a straight or branched alkyl group containing 8 to 16 carbon atoms at the 2- or 3-position of the morpholino ring, and R2 is a straight or branched alkyl group containing 2 to 10 carbon atoms, substituted with a hydroxyl group except in the alpha-position, or a pharmaceutically acceptable salt thereof.
