BRITISH VETERINARY POULTRY ASSOCIATION
Antimicrobials Guidelines
BACKGROUND
Therapeutic antimicrobial products are used by veterinary
surgeons in the treatment and control of many types of infection
in a wide variety of animal species. If a number of animals in a
group have overt signs of disease, both sick and healthy animals
may need to be treated with therapeutic levels of an
antimicrobial product for the recommended period. This is
intended to cure the clinically affected animals, reduce the
spread of disease and prevent clinical signs appearing in the
remainder.
Antimicrobial resistance is a natural phenomenon which is an
inherent risk associated with any use of antimicrobial medication
in any species. Opinion is divided on the practical effects of
any resistance associated with antimicrobial use in animals on
human health. However, measures aimed at limiting the development
of resistance are important for prolonging the useful life of all
antimicrobials in both human and animal medicine.
Antimicrobial substances used for digestive enhancement are
administered in small amounts in the feed. Their use has been
carefully controlled in the UK for over 20 years, and the
principles laid down by the Swann committee have now been
incorporated in European regulations. These products are used in
livestock production with a view to improving the efficiency of
digestion of animal feeds. In addition they may have important
ecological benefits and may reduce the prevalence of certain
diseases.
GUIDING PRINCIPLES
- 1. Therapeutic antimicrobial products should not be used
as an alternative to good management, vaccination, or
site hygiene.
- 2. All prescribing of antimicrobials should be for
animals under the care of the prescribing veterinarian as
defined in the RCVS Code of Conduct, and expanded on in
the BVPA Code. All prescription-only medicines should be
supplied with a prescription or direction, a copy of
which should be retained by the prescriber for at least 3
years.
- 3. The use of therapeutic antimicrobial products in the
absence of clinical disease or specific pathogenic
infections and, in particular, long-term administration
to prevent disease should not be practised without a
clear justification.
- 4. In an outbreak of animal disease, the sensitivity of
the causal organism should ideally be ascertained before
therapy is started. In disease outbreaks involving high
mortality or where there are signs of rapid spread of
disease among contact animals, treatment may be started
on the basis of clinical diagnosis. Even so, the
sensitivity of the suspected causal organism should,
where possible, be determined so that if treatment fails
it can be changed in the light of the results of
sensitivity testing. Antimicrobial sensitivity trends
should be monitored over time and such monitoring may be
used to guide clinical judgement on antimicrobial usage.
- 5. It is recognised that prophylactic
medication may be appropriate in certain precisely
defined circumstances. Each practice should develop a
written policy or protocol covering the circumstances in
which this is considered appropriate.
- 6. Detailed preventative medicine programmes should be
documented for all companies and/or farms. These should
include all routine medications (including non-prescription
medicines such as anticoccidials, digestive enhancers,
anthelmintics), competitive exclusion and probiotic
treatmentsand vaccines. Any prescribing of antimicrobial
medication should be made taking into account its
possible effects on other aspects of the programme.
- 7. Any use of antimicrobials outwith
the above guide-lines, in particular use of
antimicrobials outside normal data-sheet recommendations
(in accordance with “the cascade”) should be
carefully justified, for instance as part of the written
prescription.
- 8. In all uses of antimicrobials the best available
information should be used to determine treatment regimes
and dosages aimed at providing optimal efficacy with
minimal risk of collateral resistance development in
either the target organisms, potentially zoonotic
organisms, or organisms capable of transmitting
resistance to pathogens. The marketing authorisation
holder will be the normal source of such information.
- 9. It is acceptable and desirable for QA schemes to
monitor antimicrobial usage, medication documentation,
and withdrawal period compliance. However such schemes
should not prevent the attending veterinarian from
preventing suffering in the animals under his care.
Tracking of antimicrobial usage should take into account
varying product potency. The simplest approach is to
record the number of Kgs. of animal treated/day as a
proportion of the total Kgs. of animal at risk. Any usage
where the mg/kg dosage does not match licensed values
would need to be highlighted.
Ultimately, the use of these products depends on responsible
prescribing by the veterinary surgeon.
Addendum re. Fluoroquinolones.
In response to the House of Lords Select Committee report on
microbial resistance, in which specific reference was made to the
veterinary use of fluoroquinolones, BVPA advises its members and
other veterinarians who may be called upon to treat poultry that:
- A. Use of fluoroquinolones in commercial poultry outwith
the data sheet approved dosage, route of administration
and treatment period, is to be strongly discouraged. For
example: use of these products by dipping of eggs,
intended for hatching chicks or poults for human
consumption, should be avoided.
- B. All of the standard guidelines as outlined above need
to be followed with care, in particular paragraphs 4 and
8.
PMcM 08/98