A pet waste station at Ridges of Cascade in Grand Rapids, Mich. The high-end apartment community plans to use DNA technology as a way to sniff out dog owners who fail to pick up their pets’ feces. (Cory Morse /The Grand Rapids Press via AP)

If you live in a place of clean sidewalks and poo bag dispensers, you might believe this is a world where canine excrement is not an enormously foul public problem. You would be wrong.

Dogs in the United States and across the globe are using streets as their toilets and leaving the mess behind. Pedestrians are stepping in it. Children are possibly being sickened by it. Municipal sanitation departments are being burdened by it.

And so cities, tired of the turd, are devoting precious brainstorming hours to inventing ever-more-novel ways to combat it. The latest is Madrid, which this week announced a “shock plan” to force dog owners in two districts to clean up after their pets: Those caught not doing so must either spend a few days as substitute street cleaners or face a $1,700 fine.

The Spanish capital’s city hall said “there is still excrement in the streets, parks and other places” despite “repeated public awareness campaigns” and the distribution of millions of free poo bags, according to The Guardian.

In 2015, a survey carried out by a British poo bag company — based on its bag sales in 17 countries, so not terribly scientific — concluded that the French were the least likely to pick up their dogs’ waste. People in the United Kingdom were the most likely, and Americans came in third.

But if anti-dog doo campaigns are any guide, Spain, which came in seventh, has an epic battle on its hands. In 2015, the city of Tarragona announced a plan to use DNA testing to match droppings to dogs (a tactic that many American apartment buildings also employ). Before that, the town of Colmenar Viejo dispatched a private detective to record videos of offending dog owners, who were then fined by police.

In 2013, Brunete, a suburb of Madrid, boxed up dog feces and mailed it to scofflaw owners. For two weeks, volunteers spied on dog walkers, sidled up to those who didn’t scoop and asked the name of the pooch — which, because most were registered with the city, was usually enough information to determine the owner’s address. Mayor Borja Gutierrez told the New York Times that the problem was the No. 1 constituent complaint, and that the mail-bombs had improved things by 70 percent.

“It’s your dog, it’s your dog poop. We are just returning it to you,” Gutierrez said.

Why are such absurd programs necessary? Fortunately, someone tried to find out. Last year, Matthias Gross, a German sociologist, published an entire paper about it in the journal Environmental Sociology. Its title: “Natural waste: canine companions and the lure of inattentively pooping in public.”

It was based on years of observing dog owners in public places. Among the findings: People are more likely to pick up poop when others are around, probably because they want to be viewed as responsible. Some pretend not to see the droppings, and other awful dog owners actually go to the effort of scooping and then tossing the bag onto the ground next to a trash can or onto someone’s lawn.

“Poop on the sidewalk or anywhere else in public serves as a visual and olfactory (and, if stepped on, a tactile) conduit of communication,” Gross wrote. “Dogs become mediators for humans between wild nature and tamed culture. Perhaps it is the freedom taken away from humans to poop in nature that encourages them to project this freedom onto their best friends.”

Or maybe they’re just selfish?

In any case, the struggle continues, and the tactics grow more desperate.

In 2013, Bristol, England, put up posters of a toddler, her face smeared with something brown, next to an image of dog doo. The caption: “Children will put anything in their mouths.” Another English town fines dog owners who don’t carry poo bags, whether or not they’re needed. Volunteers in Corvallis, Ore., spray painted turds orange. Authorities in Taiwan gave lottery tickets to people who turned in their bags of dog excrement.

New York, a city whose dogs produce an estimated 100,000 tons of waste annually, for a while had signs that warned of a $1,000 fine for not scooping poop.

“A thousand dollars for something that comes out of your dog’s butt?” 11-year-old Jessie Gross said to the New York Post in 2013.

The signs weren’t accurate; the real fine is $250, and it’s mostly symbolic, because it seems that in New York wacky plans aren’t needed.

As Michael Brandow, an author the New York Post billed as an “expert on New York’s poop scoop laws,” told the paper: “City life was improved by using peer pressure to put in place a custom that was followed voluntarily.”

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