American pet owners collectively spend tens of millions of dollars every year on veterinary care and over-the-counter medicines for their furry loved ones. But what many don’t realize is that many pet illnesses can be avoided by simply keeping the backyard clear of pet waste.

Dog waste is more than just a smelly and unsightly mess. It’s also a breeding ground for infection—especially in dog parks and other areas where dogs frequently gather. Bacteria, worms and other parasites thrive in the waste until it’s cleaned up or washed into the water supply. Giardia, ringworm, roundworm and E. coli are examples of such inhabitants, all of which are commonly found in dog feces and are easily transferable upon contact.

When pets become sick, contagions are often times passed through their deposits into their own yard. The longer infected dog waste stays on the ground, the greater a contamination becomes. And when this waste is not picked up, pets have a high risk of catching the infection over and over again.

Roundworm, for example, is one of the most common parasites found in dog waste and it can remain infectious in contaminated soil and water for years.

The best thing pet owners can do to help keep their four-legged friends healthy and safe is to pick up after them and to do so in a timely manner. Those who don’t have enough time to deal with the mess themselves—or simply don’t want to—should consider hiring a local pet waste removal service.