Chytrid fungal disease has driven more amphibian species to extinction than any other disease in recorded history. Understanding this crisis highlights the welfare dimension of infectious disease in wildlife.
Chytridiomycosis causes a distressing death for infected amphibians through progressive skin dysfunction, electrolyte loss, and cardiac failure. Species that are experiencing population crashes from the disease face welfare harm at massive scale - the dying of wild populations represents enormous numbers of individual animals experiencing disease and death. The global spread through human trade demonstrates how human activities translate directly into wildlife welfare harm at species-threatening scale. The loss of entire species from ecosystems represents an irreversible welfare harm that extends beyond individual animals to entire biological communities.