Antibiotics are used in food animal production in 4 ways: therapy (treatment of infections in clinically ill animals), metaphylactics (treatment of healthy animals exposed to animals with clinical signs), prophylactics (treatment of healthy animals to prevent disease when stressed), and as growth promoters. The increasing recognition of antibiotic-resistant bacteria is a global concern. In 1995, use of antibiotics for growth promotion was banned in Denmark, and in 1997 to 1998, the European Union banned the use of avoparcin, bacitracin, spiramycin, tylosin, and virginiamycin for growth promotion in food animals. Data from a network of veterinary reference laboratories monitoring the occurrence and emergence of antibiotic resistance from food animals has shown that reduced use of antimicrobials in food animals was accompanied by reduced antibiotic resistance.
COMMENTARY: The author is a well-known advocate of limiting antimicrobial use in veterinary medicine and this review of the literature promotes this view. For example, although he admits that it is not always relevant, he reviews data on the amounts by weight of antimicrobials used in food animal production. Although the facts are correct, this is a highly biased tactic as there is a huge difference in antimicrobial "firepower" between a kilogram of penicillin and a kilogram of a fluoroquinolone. He presents the Danish model of prudent use (which includes banning subtherapeutic use and making all antimicrobials available only by prescription and only through pharmacies), but doesn't mention that it costs twice as much to produce pork in Denmark as it does in North America. In reviewing the emergence of resistance in pathogens zoonotic to humans, he does not mention the CDC's National Antimicrobial Resistance Monitoring System, whose results have shown either no changes or increased antimicrobial susceptibility in the United States. While this review is well written and the author's call for more research into appropriate antimicrobial treatment and more monitoring systems is good, it should not be viewed as the "whole story."
Veterinary drug usage and antimicrobial resistance in bacteria of animal origin. Aarestrup FM. BASIC CLIN PHARM TOXICOL 96:271-281, 2005.