Development and validation of a chronic pain perception scale for dogs: Structural validity and reliability

Background: Chronic pain affects 20–37% of dogs, with osteoarthritis as the primary cause. Chronic pain contributes to behavioural problems, negatively affecting both dogs and their caregivers. Early detection is crucial. However, no standardised tool assesses caregivers’ ability to recognise chronic pain. Methods: This cross-sectional study developed the chronic pain perception scale (CPPS), a self-reported questionnaire assessing caregivers’ ability to identify chronic pain in dogs with osteoarthritis. Psychometric properties were examined using exploratory factor analysis, confirmatory factor analysis (CFA) and composite reliability. Results: The final version of the CPPS consisted of seven items grouped into two factors: motor/sensory expression and emotional expression. An initial CFA in a larger sample showed good fit (root mean square error of approximation [RMSEA] = 0.045, p = 0.569), but concerns about factor structure led to a second CFA in a smaller sample. The final CFA showed good fit (standardised root mean square residual = 0.036, goodness-of-fit index = 0.949, normed fit index = 0.966 and comparative fit index = 0.975), despite RMSEA (0.105, p = 0.002) indicating poor fit. Limitations: The sample lacks diversity as it is composed mostly of women with internet access. Furthermore, as participants were all Portuguese, the tool's validity may not be generalisable to different languages and cultural contexts. Conclusion: The CPPS is a valid tool for assessing caregivers' ability to recognise chronic pain in dogs with osteoarthritis, supporting both research and clinical practice. It may also help improve veterinarian‒caregiver communication, enabling earlier detection and management of chronic pain.