White-nose syndrome (WNS) has killed over 7 million bats across North America since 2006, causing some species to decline by 99%. The fungal disease causes abnormal arousal from hibernation, burning fat reserves and causing starvation.
Bats with white-nose syndrome are aroused from hibernation repeatedly, consuming fat reserves that should last the winter. Bats that exhaust their fat stores emerge during winter cold to forage when insects are absent, dying of starvation and hypothermia. The process of starvation over multiple days to weeks represents significant welfare harm. Experimental treatments aim to prevent fungal growth on bat skin, which would eliminate this welfare harm while supporting population recovery.