By Marie Villani-York

If she could, Star would have chewed through the door of her sixth-floor apartment in Skyview when the doorbell rang suddenly last week. Instead, all she could do was bark and race back and forth - the click, click, click of her nails letting visitors know how close or how far she was from the door.

"Who do you think that is?" Barbara Tallerman asked her terrier mix.

Star didn't answer, but her reaction said plenty.

When the door swung open, Star shot like a furry rocket into the waiting arms of Susana Cook, her much-beloved dog walker. Sloppy wet kisses, rat-tat-tats of barks and short howling cries of joy let Ms. Cook know just how pleased her four-legged friend was with the prospect of a few hours out in the sunshine.

It's moments like these that make Ms. Cook glad she traded in paper, pens and an office for leashes, biscuits and parkland.

"Every door I open, it's like a party waiting for me," said Ms. Cook. "They're so excited to see you."

There are many hardworking Riverdale residents out there and no one knows better than the local dog walkers.

For the last 10 years, Ms. Cook has walked between five and seven dogs a day. Her bread and butter, she said, are single women who love the company of dogs but whose long work hours would suggest otherwise.

They give Ms. Cook a set of keys to their homes, and like a school bus driver, she makes her rounds, from the modest houses in North Riverdale down to the high-rises of Spuyten Duyvil, picking up eager canines bursting with full bladders.

While she's glad to throw a tennis ball in the Skyview dog run or navigate the leafy paths of Riverdale Park, the Argentina native's favorite place to take her charges is on the back trails of Van Cortlandt Park. "I tell people this is my office," she said with a chuckle. "I live here."

On a warm afternoon last week more fitting of summer than fall, Ms. Cook led Sycamore, a 7-year-old black Lab mix; Zeus, a 7-year-old Chihuahua mix; and Kirby, a 2-year-old golden retriever, along a short, winding path behind Vannie's horse stables to the newly renovated Canine Court dog run.