As a service dog in training, Layla searches her family's grocery bags, kitchen cabinets, backpacks, stairwells, playgrounds, hotel rooms and other suspicious areas for the odor she was trained to detect: peanuts.
When the young pit bull/bulldog mix detects even the tiniest scent of a peanut, she lies down on her belly, stares at the culprit and points with her paw.
Her reward: a squeaky ball.
This subtle act of heroism is a lifesaver for her Manhattan owners and their 6-year-old son, Grey, whose severe allergic reactions to peanuts and shellfish have landed him in the hospital at least a dozen times.
The boy's food allergy first reared its head when, at age 2, Grey went into anaphylactic shock after eating a peanut butter cracker that had rolled under the couch.
"We're constantly afraid that he's going to die," said his mom, Catherine Sheer, 28, who noted that Grey's allergy is so bad he can break out in hives just walking down the aisle at the Whole Foods market. "It's like living in a world where there's cyanide everywhere," she added.
Peanuts - or their scent - are all around us. Their residue, which can be in the form of butter, oil or dust, is found or left behind in schoolyards, libraries, movie theaters, on airplane seats and just about anywhere people go.
For that reason, many kids with peanut allergies are home-schooled and rarely have play dates.
"I was determined for him to have a normal life," said Sheer, who is dismayed that service dogs are not allowed in New York City's public schools.
Still, Grey attends public school in Chinatown - unlike his preschool, it is not peanut-free - where he is shadowed by a paraprofessional who makes sure the boy steers clear of any nuts. Grey's family and the school nurse are armed with epinephrine and Benadryl to treat allergic reactions.
Meanwhile, Layla, a rescued pooch, was never meant to be a peanut-detector dog. Grey and his mom were on their way home from school one day when they spotted the 4-month-old puppy playing in the window of the Animal Haven Shelter in SoHo. Layla had been flown in from an overrun Missouri shelter by Paws and Pilots as part of a big rescue effort.
It was love at first sight for Sheer when Layla licked her hand and then rolled over and went to sleep.
"She's gentle and calm and the best dog in the universe," Sheer said of the mixed breed with a bad reputation, who, despite urban myth, is even tender with her year-old baby, Scarlett.
The idea to train Layla as a scent detection dog occurred to Sheer in August during a month-long family trip to San Diego, but she was told that scent dogs are generally shepherds, poodles and golden and Labrador retrievers.
When the family took a day trip to Legoland, however, Layla stayed at the Snug Pet Resort, where trainer Mike Stone saw great promise in the loyal mutt as a "peanut dog" and agreed to try training her, Sheer said.
After spending two months out West with Stone, Layla recently returned to Manhattan, where, despite her young age and breed, she continues to show great promise as a lifesaver for Grey.
While pit bulls aren't generally used as scent dogs, Sheer believes their great desire to please their owners make them worthy of the job.