The relationship between antimicrobial resistance (AMR) and animal welfare is bidirectional and complex. Poor animal welfare increases antibiotic use, contributing to resistance; AMR then threatens our ability to treat disease, compromising future welfare. Understanding this connection is essential for sustainable approaches to both challenges.
Animals in poor welfare conditions are more susceptible to infectious disease, requiring more frequent antibiotic treatment. Key pathways include: stress-induced immunosuppression (making animals vulnerable to bacterial infection), crowding (facilitating pathogen transmission), poor hygiene (increasing pathogen load), malnutrition (impairing immune function), and suboptimal housing (creating environmental conditions that promote disease). Intensive systems with poor welfare records consistently use more antibiotics than higher-welfare systems.
Globally, livestock farming accounts for a substantial proportion of total antibiotic use—in some countries, more antibiotics are used in agriculture than human medicine. The use of antibiotics for growth promotion (now banned in the EU and increasingly restricted globally) and disease prevention in intensive systems creates selection pressure for resistant bacteria. Resistant bacteria can transfer to humans through food chains, direct contact with animals, and environmental pathways.
Improving animal welfare reduces disease incidence, directly reducing the need for antibiotics. Danish experience with the ban on prophylactic antibiotic use in pig production showed that improved husbandry (better biosecurity, higher welfare) could substitute for antibiotic use without major production impacts. Examples of welfare-AMR synergies include: reducing stocking density (less disease transmission, less antibiotic use), improving ventilation (less respiratory disease), providing enrichment (reduced tail biting means fewer secondary infections requiring treatment), and optimising nutrition (stronger immune responses).
Moving from prophylactic (preventive) group antibiotic treatment to targeted treatment of individual sick animals is both a welfare improvement (healthy animals do not receive unnecessary drugs) and an AMR stewardship measure (reducing selection pressure). This shift requires improved disease monitoring and stockperson training in early disease detection—investments that benefit welfare alongside resistance management.
The emergence of resistance threatens the long-term availability of effective treatments for animal diseases. If common livestock pathogens become untreatable, the welfare consequences would be devastating—animals suffering from diseases that veterinary medicine can no longer control effectively. Responsible antibiotic stewardship in agriculture protects future welfare by preserving therapeutic efficacy.
Addressing the AMR-welfare nexus requires a One Health approach integrating human health, animal health, and environmental considerations. The interdependence of antibiotic use in different sectors means that stewardship in agriculture is inseparable from stewardship in human medicine. Regulatory frameworks, farm assurance schemes, and retailer standards that incentivise welfare improvement and responsible antibiotic use are both welfare tools and public health protections.