“…In this review article, we provide an overview of the HPA axis, describe the primary actions of glucocorticoids and DHEA(S), discuss the pathophysiological effects of HPA dysfunction, and consider how the ratio of glucocorticoids to DHEA(S) may be applied to animal welfare research. However, we should note that while the cortisol:DHEA(S) ratio has been employed in studies of human development, psychology and immunology, there has been relatively little research on how this ratio may provide insight into the physical, mental and emotional health of non-human animals [ 15 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Therefore, we will explore the benefits of integrating this biomarker into animal welfare monitoring schemes and discuss potential methods for applying this metric in managed care settings.…”