Cows with mastitis caused by Mycoplasma bovis (M. bovis) are generally subjected to preventive culling rather than treatment even if the infection is subclinical as they can be a source of severe infection, thereby causing significant economic loss to dairy farmers. We performed dry period therapy based on antimicrobial susceptibility on cows with subclinical mastitis caused by M. bovis. Marbofloxacin and pyrulimycin were selected as susceptibility antibiotics in this study. Overall, 16 cows with subclinical M. bovisudder infection were categorized into treatment (n=8, administered with antibiotics for 5 days before routine dry cow therapy) and control (n = 8, administered with routine dry cow therapy only) groups. Postpartum milk was M. bovis-positive in 0% (0/8) and 25% (2/8) cows in the treatment and control groups, respectively. The findings of this study suggest that the correct choice of antibiotics and treatments can completely cure M. bovis subclinical udder infections, thereby preventing unnecessary culling.