Toxoplasma gondii is a ubiquitous obligate intracellular apicomplexan parasite that can infect many species of mammals and birds worldwide. Cats harbor high quantities of T. gondii in their digestive tract and serve as definite hosts. One infected cat is able to shed up to 100 million oocysts in their feces in less than a 2 week period. These oocysts are able to sporulate and become infectious to chickens in 1 to 5 days, and are able to remain in the environment for at least one year, usually longer depending on the environment.
It is recognized that T. gondii serves as a foodborne risk and infection is common in many domesticated animals used for food in the US, including pigs, chickens, lambs and goats. Chickens are often infected through contamination of T. gondii ooysts with the environment. Contamination is predicted as widespread throughout the United States, as a result of fecal contamination of soil and ground-water by the estimated 140 million domestic and feral cats in the US, each of which can deposit hundreds of millions of oocysts in feces during infection.