White-nose syndrome has killed over 6 million North American bats since 2006, with promising treatments now being applied to hibernating bats in a race against an advancing epidemic.
White-nose syndrome creates individual animal suffering on an enormous scale. Affected bats wake from hibernation in winter conditions — cold, no food insects flying, fat reserves depleted — and face a lingering death from starvation and exposure. The fungal infection itself causes skin and wing membrane damage that is physically painful. The individual welfare emergency of millions of bats dying slowly through winter is matched by the population-level catastrophe of 90-99% declines in some species. Treatment programs that can arrest this progression represent welfare intervention at a scale rarely achievable for wild animals.