For decades, scientists have warned that ecologically destructive activities increase the risk of diseases spilling over between wildlife and human populations. Examples of these drivers include climate change, habitat loss, wildlife trafficking, environmental contamination, expansion of anthropocentric activities and invasive species introduction. Domestic animals also contribute to the movement of diseases between species. Free-roaming domestic animals, like cats, can facilitate the spread and transfer of diseases, impacting both humans and wildlife. Infectious parasites Free-roaming cats — which include feral, stray and house cats — present a particularly compelling case because of their large population sizes and their central role in the life cycle of a parasite called Toxoplasma gondii ( T. gondii ) that infects both wildlife and humans. Most people may have only heard of toxoplasmosis from their doctors during a pregnancy or in articles on "brain-altering"