Chronic Stress as a Driver of Behavioral-Immune Dysregulation in Animals: Implications for One Health and Pathogen Resilience

This narrative review attempts to provide a conceptual and integrated perspective within the One-Health framework to present the impact of chronic stress on immune function and behavioral patterns in animals. Chronic stress can suppress specific components of adaptive immune, alter social-nutritional-exploratory behaviors, and promote mild but chronic inflammation by continuously activating the hypothalamic-pituitary-adrenal (HPA) axis and through glucocorticoid-dependent changes, and subsequently reduce resistance to disease, increase susceptibility to infection, prolong disease duration, and increase the dynamics of pathogen transmission in domestic, farmed, and wildlife animals. Understanding the link between behavior and neuroendocrine responses and immune consequences of chronic stress allows for a holistic and interdisciplinary view of animal, environmental, and human health and welfare issues, and can be a basis for developing preventive strategies in animal health and welfare management in veterinary medicine and one health. Using an interdisciplinary approach can also be considered in other biomedical fields as a new framework for better understanding the mechanisms of diseases and functional connections between different body systems.