The following is written by Meredith Li-Vollmer of Public Health Insider:

You’ve probably not heard the words “raccoon” and “latrine” put together. For instance, it’s doubtful that you’ve heard, “So, what’s up with the raccoon latrine in the corner of your yard?” uttered at the neighborhood block party.

But it is a thing. A raccoon latrine is a site where those furry, masked critters repeatedly deposit their feces in one particular spot. Raccoons prefer sites that are flat and raised off the ground, but they also use the base of trees, and occasionally, open areas. Common sites for raccoon latrines are roofs, decks, unsealed attics, haylofts, forks of trees, fence lines, woodpiles, fallen logs, and large rocks.

It’s never pleasant to have a latrine on your property, no matter who is using it. But if it was created by raccoons, it’s also a health hazard.

Danger from roundworms (this is where it gets gross)

A raccoon latrine is very likely to contain roundworm eggs. The raccoon roundworm (Baylisascaris procyonis) lives in the raccoon’s intestine and produces microscopic eggs that are shed in the raccoon’s feces. One raccoon roundworm can produce more than 100,000 eggs a day.

A raccoon can pass millions of eggs in its feces everyday, depending on how many worms are in its intestines. Once deposited in the environment, the eggs develop into the infectious form in 2-4 weeks, and can survive in the soil for several years.

If these infectious eggs are inadvertently swallowed by humans or other animals, larvae hatch out of the eggs and move into the host’s organs. The larvae travel throughout the body and may cause serious eye disease, spinal cord or brain damage, or even death. Infections from raccoon roundworms are rare, but can be very serious.

Preventing illness from raccoon roundworms

You can prevent having a raccoon latrine on your property by discouraging raccoons from frequenting your outdoor living space. Don’t leave human or pet food out where raccoons can get to it, and keep your garbage storage secure. Close off any possible entrances to your attic or under your house or decks.

If you discover a raccoon latrine on your property, keep children and pets away from that area. The latrine area will need to be cleaned using special precautions to prevent contaminating other surfaces or accidentally swallowing any roundworm eggs. It’s particularly important to avoid stirring up debris and to wear protective gear, such as N95-rated particle masks and disposable gloves and booties.

Public Health’s Animal, Bugs, and Pests page has more information about what raccoon latrines look like and how to clean them, as well as other critter-related health topics.  The Washington Department of Fish and Wildlife is also a great source of information about raccoons.

For more about Public Health – Seattle & King County, please see our official website, at http://www.kingcounty.gov/healthservices/health.aspx.