Stress in Domestic Animals: A Psychoneuroendocrine Approach

Abstract

The concept of stress originates with the recognition that the milieu interieur of many living species is kept within fixed limits despite a wide range of environmental conditions and metabolic needs (homeostasis). Stress was therefore considered a strain on homeostatic mechanisms exceeding normal adaptive capacities. The emphasis was first on hormonal systems involved in adaptation, mainly catecholamines and pituitary-adrenal hormones. Because studies were at that time based on autopsy findings and histological results, stressors used were extreme, e.g., hemorrhage, fractures, or extensive burns.