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VetBooks.ir Chapter 7

Regulatory Aspects for the Drugs

and Chemicals Used in Food-Producing

Animals in the European Union

´
Arturo Anadon, Marı´a R. Martı´nez-Larran ˜ aga, Irma Ares and Marı´a A. Martı´nez

health hazard and could create problems in international
INTRODUCTION
trade, in particular, those substances that have no
Drugs and chemicals are essential for the production of acceptable daily intake (ADI) and no international MRLs,
animals intended for food. They are administered orally or or their MRLs do not cover species and uses that were
systemically to treat animals or prevent disease and also to considered minor by the availability of the data. The estab-
promote growth and feed efficiency. The European Union lishment of the MRL represents one of several standard
(EU) has already banned antibiotics growth promoters options for risk managers to limit the presence of
such as avoparcin, ardacin, zinc bacitracin, virginiamycin, unwanted substances.
tylosin phosphate, spiramycin, monensin sodium, salino- The EU took major action by introducing require-
mycin sodium, avilamycin, and flavophospholipol from ments for MRLs for residues of veterinary drugs in foods
being added to animal feed due to the fact that the use of animal origin. Residues are traces of the drug and its
of these substances could lead to the selection of metabolites that remain in the animal and its edible pro-
antimicrobial-resistant strains of bacteria (Anado ´n and ducts after treatment with veterinary medicinal products.
Martı ´nez-Larran ˜aga, 1999; Anado ´n, 2006). Individual ani- Depending on the nature of the chemical and its metabo-
mals may be treated (i.e., individual injection or by oral lites, they may pose hazards with concurrent risks to
gavage), but it is often more efficient to treat entire groups consumers when the concentrations are above a safe
by mass application via drinking water or feed. According limit. For instance, certain substances having a thyro-
to the prudent use of antimicrobials in veterinary medi- static, estrogenic, androgenic or gestagenic action may
cine, routine prophylaxis must be avoided; prophylaxis be dangerous for consumers and may also affect the
should be reserved for exceptional case-specific indica- quality of foodstuffs. The concern for hormonal residues
tions. Certain mass-medication procedures, called meta- focuses on chronic exposure to low doses rather than an
phylaxis, are employed in an attempt to treat animal acute exposure to high doses. In summary, hazards may
disease outbreaks while medicating others in the group of be toxicological, pharmacological, or microbiological in
clinically healthy, but presumably infected, in-contact ani- nature.
mals to prevent disease. Antimicrobial metaphylaxis The detection of low levels of residues of certain pro-
should never be used in place of good management prac- hibited veterinary drugs in imported animal products by
tices. It is a continuing concern of consumers that various laboratories in the EU at the end of 2001 and during the
drugs and chemicals may be found at above maximum res- first months of 2002 triggered a discussion within
idue limits (MRLs) in food. The possible effect of such the Codex Alimentarius Commission (CAC) on whether
drugs and chemicals on human health and safety depends and how the problems causing such events could be
on the level of exposure to animals, in particular through addressed. Several control laboratories in member coun-
the foods we eat. Foods containing residues of any tries of the EU detected trace amounts of chloramphenicol
pharmacologically active substances (drugs and biocides) and nitrofurans in imported animal products (e.g., shrimp
or other undesired substances (pesticides or other chemi- and chicken). These findings were triggered mainly by
cals) above the MRLs could potentially constitute a public improved analytical methods that significantly lowered

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