Western Toads have seen significant losses throughout their overall distribution, although there is little evidence of major declines in Canada. Western Toads are explosive breeders with many females laying eggs at the same time which can lead to population crashes if breeding sites are impacted by random catastrophes like extreme weather or large-scale anthropogenic disturbance. Intense UV radiation may also impact the hatching success of Western Toads. Game fish that are stocked in lakes where Western Toads occur may be a major threat as fish may predate tadpoles and introduce pathogens. Due to the dense migration of newly transformed toadlets, roads and cars may cause high levels of mortality to migrating individuals. The biggest threat to Western Toads in British Columbia is habitat loss and fragmentation. The draining and eradication of wetlands removes breeding sites and reduces the potential for re-establishment of depleted or extirpated populations. Pathogens, such as Chytrid fungus and Ranavirus, can cause mass mortality of frog and toad populations. Although these pathogens are present in Western Toad populations in Canada, population decline and extirpation from disease outbreaks appear to be rare.