MASSAPEQUA, N.Y. (CBSNewYork) – Imaging leaving your dog with a trusted sitter, then suddenly it’s gone.

That’s what happened to a Long Island family who hired their sitter through a popular app.

Mary Ellen Humphrey and her children had to cut their Disney vacation short to frantically search Long Island animal shelters for their beloved dog, Buddy. He was lost by a sitter they hired through the pet sitting app Wag.

“We’re devastated, we don’t know where he is. And I’m sure he’s sad and afraid,” she told CBS2’s Carolyn Gusoff.

“We’re so miserable without him,” her child added.

The California-based service is hailed as the Uber for dog walking.

A spokesperson called the situation a perfect storm. Buddy, a 1-year-old Beagle-Lab mix, was dropped off with no collar, and his harness was removed for comfort. On Wednesday, he pushed open the front door of a Massapequa home and darted away.

The sitter was too distraught to speak.

“She feels terrible about what happened, and this was a total accident,” Wag spokesperson Dini Von Mueffling said. “This is a very, very rare occurrence in the history of Wag.”

The company is posting 1,000 lost dog flyers, notifying local police, vets and shelters, issuing a pet Amber Alert, and even hiring drone pilots to search from above.

This isn’t the first time a dog under Wag care has gone missing. Two years ago, a Brooklyn Chihuahua disappeared. It was later hit by a car and died.

The spokesperson said the company’s handlers are thoroughly vetted and tested. Fewer than five percent of applicants make the cut.

One sighting near John J. Burns Park suggests Buddy may have been nicked by a car.

“He may been injured and he’s probably afraid, and we really need to get him,” Humphrey said.

Other dog owners feel her pain.

“It can be very stressful, but it does happen,” one man said.

When it happens, local animal shelter officials optimistically report the majority of dogs are reunited with their owners. It helps that Buddy has an impacted ID microchip.

Wag is also offering a $1,000 reward and has set up a hotline for Buddy sightings, which can be reached at 818-527-2498.