Chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) has driven over 90 amphibian species to extinction and continues to cause mass mortality events with significant individual welfare impacts.
Chytrid disease causes a welfare-relevant death process in amphibians. As Bd infection progresses, affected amphibians display lethargy, loss of righting reflex, abnormal skin postures, and convulsions before cardiac arrest. The prolonged decline over days to weeks, combined with neurological symptoms, represents significant welfare compromise for animals whose sentience is increasingly recognised. Mass mortality events cause suffering at population scale. Welfare interventions at individual level are possible for charismatic or rare species using antifungal treatment (voriconazole baths), but are impossible at wild population scale. Conservation focus is on biosecurity to prevent Bd spread, probiotic treatments using beneficial skin bacteria, and selective breeding for Bd-resistant individuals in captive assurance programmes.