The Use of Hair Cortisol for the Assessment of Stress in Animals

The document reviewed the use of hair cortisol concentrations (HCCs) as an indicator of chronic stress in animals, emphasizing its advantages over other biological matrices due to its minimally invasive nature and ability to reflect long-term stress. It noted that HCCs effectively indicated stress when the hypothalamic-pituitary-adrenal (HPA) axis was repeatedly stimulated, although single stress events might not significantly alter HCCs. Various factors, including social environment, nutritional stress, medical disorders, and individual characteristics like age, sex, and hair color, influenced HCCs. The review highlighted the need for standardized sampling protocols and further research to understand cortisol incorporation mechanisms and the impact of different factors on HCCs.