The scoopers, who also handle cat, goose and deer waste, typically place it in plastic bags and, depending on local ordinances, dump it in the homeowner’s trash or drop it off at local landfills or incinerators. Their growing popularity parallels that of styling boutiques and travel services that have sprung up to help Americans spend about $45 billion on their pets each year.

Image Mr. Patterson cleans up after Daisy, Lashelle and Mark Daviss white German shepherd, at their West Harrison home. Credit... James Estrin/The New York Times

Mr. Sichler said he and his wife ran a pet-food delivery business in the late ’90s and got into waste removal in 2001 after an epiphany: “We hated cleaning up after our own dogs, and we wondered if other people hated it as much and would pay someone else to do it.”

The latest survey by the American Pet Products Association estimated that in 2008, Americans owned 94 million cats and 78 million dogs. There were pets in 71 million households, or 62 percent of all homes  up from 56 percent in 1988. Enter the scoopers, which Cheresee Rehart, the president of their professional association, said range from “a guy completely happy with 20 customers” and an income of $30,000 a year to multimillion-dollar chains with franchises.

The service Mrs. Davis uses is DoodyCalls, a Virginia company founded in 2004 that now operates from 42 sites in 21 states. Its Web site proclaims: “Woof-woof waste does not a good fertilizer make. It is actually toxic to your lawn.”

But for harried customers, convenience trumps all other incentives. “We sell time,” said the company’s founder, Jacob D’Aniello, 32, a former technology consultant.

One customer, Kevin Durkin, 50, a stay-at-home father of two in the Westchester hamlet of Katonah, said it fell to him to retrieve the waste produced by his black Labrador, Savannah, until he spotted a DoodyCalls ad and signed up for the service this spring. “It’s just something else I don’t have to take care of,” he said on a recent Monday morning as he watched Mr. Patterson, his DoodyCalls “technician,” traverse the lawn in a grid pattern.

“Go through the flower beds, too!” Mr. Durkin shouted from the porch.

Mr. Patterson, 26, whose previous job was stocking supermarket shelves, said his fiancée laughed when she first heard about his new vocation. But he said he enjoys working outside and makes sure he uses a long-handled scoop to keep a safe distance from the waste. He is one of five scoopers employed by the franchise, earning about $15 an hour.