White-nose syndrome, caused by the fungus Pseudogymnoascus destructans, has killed millions of North American bats and represents a catastrophic welfare and conservation emergency.
WNS causes a protracted and welfare-concerning death process: infected bats arouse repeatedly from hibernation, burning fat reserves through increased metabolic activity, and eventually starve before spring insect prey becomes available. Bats found outside hibernacula in winter are typically WNS-affected and near death. Individual bat welfare during WNS is difficult to address at scale — the disease spreads through cave systems affecting millions of animals. Welfare interventions include: emergency supplemental feeding programmes (mealworm provision near affected caves), probiotic treatments being tested by researchers, and ultraviolet light treatment of hibernacula to reduce fungal load. The Bat Conservation Trust and White-nose Syndrome Response Team coordinate research and emergency response.