Antibiotic Residues in Milk as a Consequence of Mastitis Treatment: Balancing Animal Welfare and One Health Risks.

Bovine mastitis is a prevalent infectious disease in dairy cattle, causing inflammation, pain, reduced milk yield, and economic losses. Antibiotic therapy is the mainstay of treatment, yet irresponsible use can lead to the presence of antibiotic residues in milk and contribute to the emergence of antimicrobial resistance (AMR), posing significant risks to public health and food safety. This review aims to provide a comprehensive synthesis of current knowledge on mastitis management, antibiotic use and resulting residues in milk, their public health and environmental impacts, and alternative strategies to reduce antibiotic dependence, framed within a One Health-One Welfare perspective. Antibiotic residues in milk are closely linked to treatment practices, withdrawal period compliance, and regulatory oversight, with prevalence ranging from <1% in some European countries to over 80% in parts of Africa. Residues, particularly from β-lactams, tetracyclines, and quinolones, can disrupt human intestinal microbiota, promote resistant bacterial strains, trigger immunological reactions, and interfere with dairy processing. Environmental contamination through excreted antibiotics further facilitates the spread of resistance. Sustainable alternatives, including probiotics, phytotherapy, vaccines, and improved farm biosecurity, show promise in reducing antibiotic use while maintaining animal welfare and productivity. Antibiotic therapy remains essential for mastitis control, but its consequences on milk safety, public health, and AMR require prudent management. Integrating monitoring, adherence to withdrawal periods, and sustainable alternatives within a One Health-One Welfare framework is critical for ensuring safe, responsible, and environmentally sustainable dairy production.