Terms and concepts for veterinarians to make decisions for the selection and judicious use of antibiotics in animals. Benefits and limitations of antibiotic susceptibility testing options and how to interpret a drug label. Agencies involved in antibiotic regulation and resistance and residue monitoring and a review of the Animal Medicinal Drug Use Clarification Act and extra-label use of drugs. Numerous resources to assist in making informed decisions on antibiotic use in animals are also included.