Stress is a physiological response to perceived threats. Understanding the difference between adaptive acute stress and welfare-compromising chronic stress helps owners and carers provide genuinely good conditions for animals.
The distinction between acute and chronic stress is fundamental to welfare assessment. A dog briefly startled by a car backfire experiences acute stress that resolves quickly - a normal, adaptive response. A dog left alone for 10 hours daily who develops separation anxiety experiences chronic HPA axis activation - a welfare problem. Chronically stressed animals have measurably impaired immune function, making them more susceptible to disease; impaired reproduction; and may develop stereotypic behaviors as coping mechanisms. The welfare science of stress allows objective measurement of conditions that might otherwise seem subjective. High cortisol measures in farm animals correlate strongly with welfare-compromising housing, management, and human-animal relationship quality.