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Antimicrobial Resistance - Prudent Use


Antimicrobials have been important tools in the control of infectious diseases since the 1950s. Their use in veterinary medicine has improved the health and welfare of animals. Antimicrobial use has also contributed to the production of meat, milk and eggs which are safe for both the consumer, and the people involved in food production.

The CVMA recognizes the emerging implications of antimicrobial use on human health. The continued use of antimicrobials in veterinary medicine depends upon the profession’s ability to use these products wisely and finding the balance between maximizing animal welfare and conserving antimicrobial efficacy.

General Principles:

  • Veterinarians, animal owners and animal caretakers all share responsibility for minimizing the use of antimicrobial drugs to conserve drug efficacy.

  • Antimicrobial treatment regimens should be designed to maximize therapeutic efficacy while minimizing bacterial resistance.

  • Antimicrobials used in animals should only be used within the confines of a valid veterinarian-client-patient relationship (VCPR)1.

  • Veterinarians should continually update their knowledge of methods of disease prevention, new therapeutics and of other issues such as drug resistance trends, to ensure the prudent use of antimicrobials.

  • All users of antimicrobials should be educated in the proper use of antimicrobials including administration, handling, storage, disposal and record-keeping. Veterinarians have a responsibility to educate staff, clients and other animal handlers on the prudent use of antimicrobials and for ensuring such training occurs.


Specific Principles:

1.    All antimicrobials, even those not purchased directly through or on prescription from a veterinarian, should be used within the confines of a valid VCPR.

2.    Animal owners and caretakers should be instructed in and encouraged to implement management, immunization, housing and nutritional programs that prevent or reduce the incidence of disease and therefore antimicrobial use.

3.    Antimicrobials should only be used therapeutically if a pathogen is demonstrated or anticipated to be present, based on clinical signs,

history, necropsy examinations, laboratory data (including resistance testing), and if the pathogen is expected to respond to treatment.

4.    The need for prophylactic antimicrobials should be regularly assessed. Prophylactic antimicrobials should only be used when an animal(s) is determined to be at risk and evidence indicates that such usage reduces morbidity and/or mortality. Surgical protocols should emphasize strict aseptic technique instead of prophylactic antibiotics.

5.    Antimicrobials should only be used to promote growth and feed efficiency if such use does not compromise therapeutic use in animals and people. Only those products currently approved should be used as growth promotants.

6.    Antimicrobial selection should be based on the known or suspected target organisms, their known or predicted antimicrobial drug susceptibility, the site of infection, knowledge of the drug including its pharmacokinetic and pharmacodynamic properties, and other factors such as host immunocompetence. Antimicrobials that specifically target the pathogen should be selected over broader-spec- trum agents and local therapy should be selected over systemic therapy when appropriate.

7.    Antimicrobials with unique mechanisms of action or novel resistance profiles in human medicine should not be used in veterinary medicine, particularly food animals, unless other antimicrobials by use or sensitivity test- ing have been shown to be ineffective and use of the antimicrobial is considered to be life-saving in the animal.

8.    Antimicrobials approved for the treatment of the diagnosed condition should be used whenever possible. The dose, frequency and duration stated on the label should be followed whenever possible.

9.    Combinations of antimicrobials, compounding of active pharmaceutical ingredients and extra-label usage of antimicrobials should be avoided unless safety and efficacy have been documented.

10. Antimicrobials should be used for the shortest time period required to reliably achieve a cure. This minimizes exposure of other bacterial populations to the antimicrobial.

11. Appropriate withdrawal times for antimicrobials used in animals intended for food should be adhered to.

12. Animals treated with antimicrobials may shed resistant bacteria into the environment. If possible, steps should be taken to minimize environmental contamination.

13. Antimicrobial products should be handled and stored properly. This includes proper disposal to avoid environmental contamination by the antimicrobial drug.

14. Veterinarians should alert any person handling antimicrobials of any potential risk to themselves and other species.


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

  • 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.

  • 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.

  • 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.

(Adopted July 1999) (Revised Dec. 23, 1999)

  • Veterinarians, animal owners and animal caretakers all share responsibility for minimizing the use of antimicrobial drugs to conserve drug efficacy.

  • Antimicrobial treatment regimens should be designed to maximize therapeutic efficacy while minimizing bacterial resistance.

  • Antimicrobials used in animals should only be used within the confines of a valid veterinarian-client-patient relationship (VCPR)1.

  • Veterinarians should continually update their knowledge of methods of disease prevention and control.

Reference Documents:

1. CVMA Guidelines on the Prudent Use of Antimicrobials in Cattle$=activity

2. CVMA Guidelines on the Prudent Use of Antimicrobials in Swine

3. American Association of Equine Practitioners Prudent Drug Usage Guidelines (Approved by the AVMA Executive Board June 2001)

4. Prudent Drug Usage Guidelines- American Association of Bovine Practitioners (AABP)

  • The production of safe and wholesome animal products for human consumption is a primary goal of members of the AABP. In reaching that goal, the AABP is committed to the practice of preventive immune system management through the use of vaccines, parasiticides, stress reduction and proper nutritional management. The AABP recognizes that proper and timely management practices can reduce the incidence of disease and therefore reduce the need for antimicrobials; however, antimicrobials remain a necessary tool to manage infectious disease in beef and dairy herds. In order to reduce animal pain and suffering, to protect the economic livelihood of beef and dairy producers, to ensure the continued production of foods of animal origin, and to minimize the shedding of zoonotic bacteria into the environment and potentially the food chain, prudent use of antimicrobials is encouraged. Following are general guidelines for the prudent therapeutic use of antimicrobials in beef and dairy cattle.

  • The veterinarian’s primary responsibility to the client is to help design management, immunization, housing and nutritional programs that will reduce the incidence of disease and the need for antimicrobials.

  • Antimicrobials should be used only within the confines of a valid veterinarian-client-patient relationship; this includes both dispensing and issuance of prescriptions

  • Veterinarians should properly select and use antimicrobial drugs.

  • Veterinarians should participate in continuing education programs that include therapeutics and emerging and/or development of antimicrobial resistance.

  • The veterinarian should have strong clinical evidence of the identity of the pathogen causing the disease, based upon clinical signs, history, necropsy examination, laboratory data and past experience.

  • The antimicrobial selected should be appropriate for the target organism and should be administered at a dosage and route that are likely to achieve effective levels in the target organ.

  • Product choices and regimens should be based on available laboratory and package insert information, additional data in the literature, and consideration of the pharmacokinetics and pharmacodynamics of the drug.

  • Antimicrobials should be used with specific clinical outcome(s) in mind, such as fever reduction, return of mastitic milk to normal, or to reduce shedding, contagion and recurrence of disease.

  • Periodically monitor herd pathogen susceptibility and therapeutic response, especially for routine therapy such as dry cow intramammary antibiotics, to detect changes in microbial susceptibility and to evaluate antimicrobial selections.

  • Use products that have the narrowest spectrum of activity and known efficacy in vivo against the pathogen causing the disease problem.

  • Antimicrobials should be used at a dosage appropriate for the condition treated for as short a period of time as reasonable, i.e., therapy should be discontinued when it is apparent that the immune system can manage the disease, reduce pathogen shedding and minimize recurrence of clinical disease or development of the carrier state.

  • Antimicrobials of lesser importance in human medicine should be used in preference to newer generation drugs that may be in the same class as drugs currently used in humans if this can be achieved while protecting the health and safety of the animals.j.    Antimicrobials labeled for use for treating the condition diagnosed should be used whenever possible. The label, dose, route, frequency and duration should be followed whenever possible.

  • Antimicrobials should be used extra-label only within the provisions contained within AMDUCA regulations.

  • Compounding of antimicrobial formulations should be avoided.

  • When appropriate, local therapy is preferred over systemic therapy.

  • Treatment of chronic cases or those with a poor chance of recovery should be avoided. Chronic cases should be removed or isolated from the remainder of the herd.

  • Combination antimicrobial therapy should be discouraged unless there is information to show an increase in efficacy or suppression of resistance development for the target organism.

  • Prophylactic or metaphylactic use of antimicrobials should be based on a group, source or production unit evaluation rather than being utilized as standard practice.

  • Drug integrity should be protected through proper handling, storage and observation of the expiration date.

  • Veterinarians should endeavor to ensure proper on-farm drug use.

  • Prescription or dispensed drug quantifies should be appropriate to the production-unit size and expected need so that stockpiling of antimicrobials on the farm is avoided.

  • The veterinarian should train farm personnel who use antimicrobials on indications, dosages, withdrawal times, route of administration, injection site precautions, storage, handling, record keeping and accurate diagnosis of common diseases. The veterinarians should ensure that labels are accurate to instruct farm personnel on the correct use of antimicrobials.

  • Veterinarians are encouraged to provide written guidelines to clients whenever possible to describe conditions and instructions for antimicrobials use at farm or unit.

  • (Board approved March 1999) (Presented by Bob Smith from the Bacterial Resistence and Prudent Therapeutic Antimicrobial Use committee)