The widespread prophylactic use of antibiotics in livestock production compromises animal welfare indirectly through antimicrobial resistance development while also masking poor husbandry conditions that directly cause welfare problems.
The relationship between antibiotic use and animal welfare is complex and bidirectional. Antibiotics can improve welfare by treating bacterial infections that cause suffering. However, prophylactic antibiotic use often functions to compensate for poor welfare conditions including overcrowding, inadequate biosecurity, and high stress that predispose animals to disease. Reducing prophylactic antibiotic use without improving underlying husbandry conditions leads to disease outbreaks and welfare deterioration. The most welfare-positive approach combines antibiotic stewardship with genuine welfare improvement: reducing stocking densities, improving housing, ensuring good stockmanship, and implementing vaccination programs. Countries that have successfully reduced livestock antibiotic use like Denmark and the Netherlands achieved this alongside husbandry improvements, not at the expense of animal welfare.