Chytridiomycosis — caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) — has driven the most significant vertebrate extinction event in recorded history, with welfare implications for millions of individual amphibians.
Amphibian chytridiomycosis represents a welfare catastrophe at a scale rarely acknowledged because amphibians receive less welfare attention than mammals or birds. The death mechanism — progressive skin dysfunction leading to cardiac arrest — causes suffering over days to weeks. The scale of impact — millions of individual animals affected across hundreds of species — is matched only by the speed at which it has unfolded. The disease spreads through the amphibian trade, meaning human activity is directly responsible for introducing it to previously naive populations. Welfare and conservation interests are completely aligned: preventing further Bd spread through biosecurity protects both individual animals and entire species from extinction.