Hippo welfare in zoo settings depends critically on access to adequate water depth for buoyancy, social group management, and opportunities to express natural territorial and social behaviors.
Hippo welfare is dominated by their physiological dependence on water — without adequate immersion, skin desiccation and thermal stress develop rapidly, creating acute welfare compromise that is highly visible and well-understood. Facilities providing adequate water depth and access meet the most fundamental hippo welfare requirement. The social welfare dimensions are more complex: hippo group composition management must navigate the intense territorial aggression of bulls while maintaining the social contact that reduces isolation stress. The development of training programs enabling cooperative veterinary care — reducing anesthetic risk for procedures in these physiologically challenging animals — represents a significant advance in hippo welfare management.