Amphibians are the world's most threatened vertebrate class, with over 40% of species at risk of extinction from disease, habitat loss, and climate change. Their welfare in decline deserves attention.
Chytridiomycosis causes distinctive welfare harm: the fungus infects the skin and disrupts electrolyte absorption, causing cardiac arrest. Infected animals show lethargy, loss of skin-righting reflex, and progressive organ failure over days to weeks. This is not a painless death. The scale of the crisis — with entire species being lost within years of disease arrival — means that welfare harms are occurring at unprecedented rates in wild amphibian populations globally. Captive assurance colonies for critically endangered species provide welfare-appropriate environments but involve the welfare costs of captivity for animals that evolved for complex natural habitats. Biosecurity measures to prevent disease spread — particularly in the amphibian trade — are urgent welfare and conservation interventions.