White-nose syndrome has killed over 90% of affected bat species in North America, and the welfare implications of mass mortality events alongside individual bat rescue and rehabilitation represent a complex animal welfare challenge.
The welfare dimension of WNS involves mass suffering at extraordinary scale — millions of bats dying of starvation while repeatedly awakening from hibernation in response to fungal irritation. The individual bat experience of WNS involves the physiological stress of mid-winter arousal, cold exposure outside hibernacula, and the energy depletion of fat reserves. Individual bat rehabilitation for non-WNS injuries — vehicle strikes, window collisions, cat attacks — addresses welfare at the individual level. The probiotic treatment approach represents a promising welfare intervention that could benefit wild bat populations at scale by reducing fungal growth without harming the bats or their microbiome. Bat house installation supports colony recovery by providing hibernation and roosting alternatives.