Beyond Cortisol! Physiological Indicators of Welfare for Dogs: Deficits, Misunderstandings and Opportunities

This paper initiates new conversations about using physiological indicators to assess dog welfare. There are significant concerns about construct validity - whether measures used accurately reflect welfare's complexity. We propose evidence-based frameworks to advance canine welfare assessment through improved physiological measurement protocols, challenge over reliance on isolated cortisol measurements, and present actionable recommendations for research methodologies that better consider individual variation. Current evidence demonstrates that animal welfare assessment requires multiple physiological indicators reflecting distinct biological systems. In practice, indicators are frequently used in isolation with limited salient dog descriptors, failing to reflect the canine experience adequately. Using a systems approach, we explore various physiological systems and alternative indicators It is essential to consider factors like age, body weight, and sex when interpreting biomarkers, and researchers should report these. This discussion identifies indicators for both positive and negative experiences. We advocate for a practical, evidence-based approach to assessing indicators of canine welfare, including noninvasive collection methods. We acknowledge the complexity of evaluating experiential responses in dogs and the need for continued work to improve practices, ultimately advancing welfare assessment and improving dogs' lives.