Pupdate: Subway Tracks Dog Escaped From UES Apartment, Family Says

UPPER EAST SIDE, NY — The dog rescued from New York City subway tracks Thursday is a rescue "angel" who bolted from her Upper East Side pad, possibly tracking his momma's scent, the pooch's family said.

The mad doggy dash caused a massive subway shutdown Thursday as transit cops tracked the runaway rover, escaped from his East 86th Street home, to a subway station three miles downtown, according to the owner's sister and police.

"We believe she was searching for her momma," the sister said. "I wouldn't be surprised that she followed her mom's scent to the subway."

The pup — whose name Patch is not publishing over privacy concerns — escaped when a new dog walker arrived at the front door and she bolted, her human aunt told Patch.

("She just couldn’t be sweeter,” she said. "I call her my niece.")

The doggo was ultimately tracked to subway tracks — New Yorkers even filmed the frantic fido rushing through a station — as the MTA stopped all trains on the 4, 5 and 6 lines just before rush hour.

"To anyone who was sitting on a train for a long time yesterday, it was not for nothing: you saved a life," the owner's sister said.

"The commuters, I’m so sorry this happened to you, but thank you very much."

Transit Officer Jose Vazquez found the pup from underneath a train car at East 23rd Street and Park Avenue, officials said on twitter. They did want to know: "Who let the dogs out?"

MTA crews cut off power to the tracks while the dog's owner crawled through the dirt to coax it out, her sister said.

The dog in question is a 2.5-year-old "shining star" of her family since her adoption from Manhattan's Muddy Paws Rescue, she said.

The pup has had hours of extensive training and has never done anything like this before, she added.

The dog's owner was at work in Brooklyn Thursday afternoon, so she hired a dog walker who happened to be new to the pooch, her sister told Patch.

When the dog walker opened the first-floor apartment door, the dog bolted out and also ran past a doorman, the sister said.

Despite the dog's dangerous day along subway tracks, all she had were few cuts, the sister said.

"She's OK," she said. "And we're extremely grateful for that,"

Both the dog and her mom are together at home Friday, recovering, the sister said.

She warned New Yorkers with dogs to make sure they're secured or behind a gate if they have a dog walker coming over. But she's also not sure how many more precautionary steps could have prevented what happened.

"This was a freak accident," she said. "I don't know if it could have been avoided."