Antibiotic resistance is a serious public health issue, but the magnitude of its
importance to animal health is poorly understood. Most of the resistance
problems in humans arise from poor antibiotic use practices in human medicine, nevertheless, there is good evidence that antibiotic use in animals
increases the prevalence of resistance in some important bacterial pathogens
of humans, including Salmonella and Campylobacter. There is increasing
pressure to ensure that antibiotic use in all fields, both human and animal, is
prudent. Regulatory authorities are also under pressure to increase controls
on approval and use of antibiotics in animals, but there is agreement that any
such controls must first be justified on scientific grounds. Particular attention
has focused on antibiotic growth promoters and antibiotics critically important
for use in humans. There is good evidence that reductions in use of growth
promoters in finisher pigs would have few adverse outcomes, but reductions in
weaned pigs should be accompanied by alternate methods to deal with
diarrhea. Critically important antibiotics should be reserved for therapeutic use
of serious bacterial infections in pigs, and group treatments of these drugs
should be discouraged.