The organic principle of health highlights ‘the wholeness and integrity of living systems’. It is not simply the absence of illness, but the maintenance of physical, mental, social and ecological well-being. We often articulate health as simply ‘disease freedom’. However, this chapter argues that if we see ‘resilience’ as a key component of health, we focus more on how we can meet the species-specific needs and challenges of each animal species, both as individuals (physical and mental well-being), as groups (social well-being), and in their surroundings and their landscapes in many different contexts (ecological well-being). The human responsibility towards animals is to understand their natural needs, organize the surroundings to allow the animals to meet them and at the same time be ready to intervene to prevent or stop suffering. The chapter gives practical and research-based examples of how to support the different aspects of animal health.