Yes because while Toxo must use cats at some point in its lifecycle it still needs to transmit to a cat in some way. This is normally done by driving rodents into "suiciding by cat" by removing any and all fear of predators resulting in death and consumption - which is precisely what the parasite needs. Prevent indoors cats from being exposed to such vectors and the chances of an indoor cat having Toxo drop to practically zero.

Mine are both indoor cats and I'm a raging anti-leftist. I think this research is great, though.