White-nose syndrome, caused by a fungal pathogen introduced from Europe, has killed over 6 million North American bats since 2006, causing suffering at a scale rarely seen in wildlife disease events.
White-nose syndrome creates mass suffering in affected bat colonies. Infected bats experience recurring arousal from hibernation driven by the fungal irritation, each event burning critical fat reserves. Bats that cannot maintain hibernation die from starvation, hypothermia, or exhaustion. The scale — millions of individual animals experiencing this prolonged mortality — is a genuine wildlife welfare emergency that receives less attention than charismatic mammal disease events. Conservation responses that reduce spread, support resistant populations, and investigate probiotic treatments address both the population-level and individual welfare dimensions of this crisis.