Hippopotamuses are semi-aquatic animals with complex social structures and specific environmental needs. Providing adequate water depth, space, and compatible social groups is essential for their welfare.
Hippo welfare in zoos hinges on water access. Without sufficient submersion time in water deep enough to support buoyancy, hippos suffer from skin desiccation — their skin secretes a red, oily fluid that acts as sunscreen and antimicrobial protection but cannot substitute for water immersion. Social management is complex: incompatible hippos fight with potentially fatal consequences, and solitary housing causes behavioral problems. Exhibit design must provide pools at least 1.5 meters deep with sufficient floor space for terrestrial movement. Breeding program participation is critical for pygmy hippos, one of the most endangered large mammals on earth. Zoos housing hippos should demonstrate investment in large naturalistic pools and evidence-based social management.