Sharon Fay, 45, of Southampton, England, said she became concerned when she spotted bits of wire sticking out of her mixed breed canine Charlie's droppings, The Mirror reported Tuesday.
"I hadn't even noticed that the lights had been chewed at this stage but it quickly became clear what had happened," Fay said. "Back in March he ate one of my scarves and needed an operation to remove it, but I thought it was just a one-off incident as he hadn't shown any signs that he was going to be a repeat offender. I've had dogs all my life and have never known a dog act like this before."
Veterinarians took an X-ray of Charlie's stomach and discovered a foot-long string of Christmas fairy lights and a shoelace.
Surgeons said the lights would have been fatal if not swiftly removed.
"A foreign body of this nature could easily have caused severe internal injuries so Charlie was very, very lucky. He was also fortunate that the glass didn't cut his mouth or throat. And he could have been electrocuted if he'd bitten through the wire when the lights were switched on," senior veterinary surgeon Sophie Bell said.
Fay said Charlie was recovering well from surgery and was back at home -- where she has taken precautions to keep him from eating other dangerous items.
Justin Bieber crashes Drake Bell's album release party
Rosie O'Donnell unveils nearly 50-pound weight loss