Amphibians are the most threatened vertebrate group on Earth, with nearly half of species at risk. Their decline represents both a conservation emergency and a welfare crisis affecting billions of individual animals.
The welfare implications of chytrid fungal disease for amphibians are severe. The fungus disrupts the skin of frogs and salamanders — a vital organ for gas exchange and osmoregulation — causing a slow, distressing death. Mass mortality events associated with chytrid outbreaks have killed millions of individual animals. The question of amphibian sentience is less resolved than for vertebrates, but behavioral evidence of pain avoidance and stress responses supports precautionary welfare concern. At a population level, the sheer scale of amphibian decline — billions of individuals of hundreds of species affected — makes this one of the largest welfare events in the history of life on Earth, largely invisible to human observation.