The antimicrobials are still important and necessary in farm and companion animal therapy, notwithstanding the increased attention and measures to promote an overall reduced and responsible use. The risk for the spread of bacterial resistance when antimicrobials are used is well known, and the interconnection of use of animal and human antimicrobials further increases the concern for human and animal health. Alternatives to these drugs are increasing, but still not routinely available. Veterinary medicine has to deal with the increasing requirement of antimicrobial use reduction, the lack of valid alternatives and a more prudent and updated use of antimicrobials in the therapy.