Amphibians face the most severe extinction crisis of any vertebrate class, with zoo conservation programs representing last resort survival for hundreds of critically endangered species.
Amphibian welfare in zoo conservation programs is technically demanding and involves species with welfare needs very different from vertebrate classes more commonly considered. Amphibians have permeable skin that is exquisitely sensitive to water chemistry, temperature, and humidity — small deviations from optimal conditions cause skin damage and systemic disease. The chytrid fungal disease that has devastated wild populations affects captive animals too, requiring strict biosecurity protocols. For many species in zoo assurance colonies, the welfare goal is not an enriched natural lifestyle but the maintenance of health for potential future reintroduction — a somewhat different welfare framework than zoo welfare for non-conservation-critical species. The conservation stakes are absolute for some species: several frog and salamander species now exist solely in zoo assurance colonies, making welfare of these populations a direct conservation necessity.