Climate change as a driver of bovine mastitis: Impacts on environmental pathogen ecology, host susceptibility, and...

Climate change poses an escalating threat to global dairy production by exacerbating the incidence and severity of bovine mastitis, a disease with profound economic and animal welfare implications. This review synthesizes emerging evidence to demonstrate that climate change acts as a multifactorial driver of mastitis risk through interconnected physiological, ecological, and epidemiological pathways. Elevated temperatures and humidity induce host immunosuppression via heat stress, compromising systemic and mammary-specific immune defenses. Concurrently, climatic variables alter the environmental dynamics of key pathogens (e.g., Escherichia coli, Klebsiella spp., Streptococcus uberis), enhancing their survival, proliferation, and biofilm formation. These changes drive extended seasonal risk windows, geographic redistribution of disease pressure, and acute spikes in incidence following extreme weather events. Furthermore, climate change intersects with antimicrobial resistance by increasing disease incidence and antibiotic use, while also promoting environmental persistence and horizontal gene transfer of resistance determinants. To address this compounded challenge, the review outlines a framework for climate-resilient mastitis control, integrating short-term heat abatement and housing adjustments, medium-term nutritional and genetic interventions, and long-term adaptive surveillance within a One Health approach. Proactive, integrated strategies are essential to mitigate the growing threat of climate-amplified mastitis and ensure the sustainability of dairy production systems. Future research must prioritize mechanistic studies, predictive modeling, and economic analyses to translate this knowledge into actionable solutions.