Cats are special hosts for T. gondii because only felines facilitate parasite sex. Infected cats excrete parasites as oocysts, which can infect just about any warm-blooded vertebrate. When they make their way into cat prey, the parasites may quickly return to a cat. In a less favorable scenario for T. gondii and human health, the parasites can end up in a person, who acquires the infection via contaminated meat, unclean produce or poor litter box technique. Credit: Source: CDC; Image by E. Feliciano; Sheep and pig: Pinare/Shutterstock