The Compassion Questionnaire for Animals (CQA) was developed to capture compassion toward animals as a multidimensional construct. While previous tools have largely assessed empathy or general attitudes toward nonhuman animals, the CQA offers a theoretically grounded approach that conceptualizes compassion for animals as a dynamic and cultivable set of abilities, encompassing affective, cognitive, behavioral, and relational components. Drawing on prior work on compassion for the self and for others, the CQA was developed through an iterative process that included expert consultation and empirical testing. The initial validation study supported a 3-factor structure underpinned by a global latent compassion factor, with strong psychometric properties and construct validity. The CQA demonstrated significant associations with empathy toward animals, nature relatedness, and more moderately, with compassion and empathy for other human beings. Age and gender emerged as relevant variables, with women and older individuals reporting higher levels of compassion for animals. To diminish the burden on participants, a shortened 18-item version (CQA-18) was subsequently developed and validated. This chapter presents the conceptual foundations of the CQA and CQA-18, details their development and validation, and discusses their theoretical and practical implications. By defining compassion for animals as a dynamic and cultivable set of abilities, the CQA and CQA-18 contribute a novel tool for advancing research on human–animal relationships, compassion training, and the moral and psychological dimensions of interspecies care. The chapter also considers the scales’ limitations and proposes future direction for cross-cultural and interdisciplinary refinement and application.