Poor animal welfare drives antibiotic overuse in livestock, which contributes to antimicrobial resistance. Understanding this connection reveals important co-benefits of welfare improvement.
The link between animal welfare and antibiotic resistance is mechanistic: welfare-compromising conditions (crowding, stress, respiratory challenges from poor air quality) suppress immune function and facilitate disease spread, requiring antibiotic intervention. Higher-welfare farms with lower stocking densities, better management, and less environmental stress use dramatically fewer antibiotics. Denmark demonstrated this by phasing out prophylactic antibiotic use and seeing improved welfare alongside reduced resistance, after an initial adjustment period. The welfare argument and the public health argument for reducing intensive livestock farming are therefore aligned — improving welfare simultaneously reduces the selection pressure driving antibiotic resistance.