| abstract |
An antimicrobial agent for animals is disclosed. The agent comprises as an effective component a racemate or a 3S-type compoundof of a pyrido[1,2,3-de] [1,4]benzoxazine derivative represented by the formula (I):n wherein R is a Cāāā alkyl group, provided that R cannot be a methyl group when the pyrido[1,2,3-de] [1,4]benzoxazine derivative is a racemate, or a salt or a hydrate thereof. The compound gives a low toxic, safe antimicrobial agent for animals, has a broader antimicrobial spectrum, and is effective against various infectious diseases of animals. |