The Five Domains model for animal welfare assessment provides a comprehensive framework incorporating mental state alongside physical welfare - its implementation in zoo practice is advancing.
The shift from Five Freedoms to Five Domains in zoo welfare assessment represents a philosophical advancement - moving from a deficit model (prevent suffering in five areas) to one that explicitly includes positive welfare as a requirement. Mental state welfare requires zoos to ask not just 'is this animal free from pain and fear?' but 'does this animal have opportunities to experience positive states?' This reframing drives different management decisions - not just eliminating obvious stressors but actively creating conditions for pleasure, interest, play and social enjoyment. Implementing Five Domains rigorously requires investment in behavioural data collection and analysis, and training zoo staff to conduct and interpret welfare assessments systematically.