Researchers to track parasite in feral cats

URBANA, Ill. -- Why did the cat cross Windsor Road?

Illinois Natural History Survey and University of Illinois researchers don't know. So they're embarking on a study of free-ranging cats near the University of Illinois' South Farms. The study might tell them not only where the felines go, but when and how often. It also might reveal the frequency with which the roving cats cross paths with livestock and wildlife such as migratory birds, not to mention with people.

That's of particular interest, in part, because cats are the "definitive host" of a parasite called Toxoplasma gondii, natural history survey scientist Nohra Mateus-Pinilla said. Which is to say that cats are the only animal known to provide a home for the parasite during its reproduction cycle, said Mateus-Pinilla, a veterinary wildlife epidemiologist and a principal investigator on two cat studies planned this year.

In addition to the South Farms research, a related project will examine free-ranging cats in the UI's Allerton Park near Monticello, providing the first look at their impact on the spread of Toxoplasma gondii to wildlife in a natural area.

Almost any warm-blooded animal can be infected with Toxoplasma gondii, which cats probably get from prey mice and the like already infected, said Milton McAllister, a pathobiology professor in the UI College of Veterinary Medicine and leading expert on the parasite.

Cats spread it in their feces by the millions. In microscopic, dormant, hard-shelled form, it can then survive for long periods in the soil, water and elsewhere waiting for another animal to infect, whether another cat, a mouse, a pig, a cow, an adult working in the garden or a child playing in a sandbox.

People probably get the parasite, which is contracted by ingestion, from unintentionally transmitting it hand to mouth, or by eating undercooked infected meat. McAllister said a quarter of the people in the United States have it, 70 to 80 percent worldwide.

"Most people who are infected do not have any symptoms at all," he said.

At worst, healthy people may suffer briefly from mild fever, sore throat or muscle aches as a result of toxoplasmosis, the condition caused by the parasite, and pass it off as a touch of the flu. But the pathogen can be dangerous, even deadly, for those with compromised immune systems.