Antibiotic – a chemical substance produced by a microorganism that has the capacity, in dilute solutions, to inhibit the growth of or to kill other microorganisms.

Antimicrobial—an agent that kills microorganisms or suppresses their multiplication or growth. This includes antibiotics and synthetic agents. This excludes ionophores and arsenicals.

Narrow Spectrum Antimicrobial—an antimicrobial effective against a limited number of bacterial genera often applied to an antimicrobial active against either gram-positive or gram-negative bacteria.

Broad Spectrum Antimicrobial—an antimicrobial effective against a large number of bacterial genera; generally describes antibiotics effective against both gram-positive and gram-negative bacteria.

Antibiotic Resistance—a property of bacteria that confers the capacity to inactivate or exclude antibiotics or a mechanism that blocks the inhibitory or killing effects of antibiotics.

Extralabel—actual use or intended use of a drug in a manner that is not in accordance with the approved labeling. This includes, but is not limited to, use in species not listed in the labeling, use for indications (disease or other conditions) not listed in the labeling, use at dosage levels, frequencies, or routes of administration other than those stated in the labeling, and deviation from the labeled withdrawal time based on these different uses.

Immunization—the process of rendering a subject immune or of becoming immune, either by conventional vaccination or exposure.

Monitoring—monitoring includes periodic health surveillance of the population or individual animal examination.

Therapeutic—treatment, control, and prevention of bacterial disease.

Veterinarian/Client/Patient Relationship (VCPR) – A VCPR exists when all of the following conditions have been met:

1. The veterinarian has assumed the responsibility for making clinical judgments regarding the health of the animal(s) and the need for medical treatment, and the client has agreed to follow the veterinarian’s instructions.
2. The veterinarian has sufficient knowledge of the animal(s) to initiate at least a general or preliminary diagnosis of the medical condition of the animal(s). This means that the veterinarian has recently seen and is personally acquainted with the keeping and care of the animal(s) by virtue of an examination of the animal(s) or by medically appropriate and timely visits to the premises where the animal(s) are kept.
3. The veterinarian is readily available for follow-up evaluation, or has arranged for emergency coverage, in the event of adverse reactions or failure of the treatment regimen.