It's the oldest story in the book: "The dog ate my homework."

However, for Payton Moody, 13, of Englewood, Colo., who slaved away for hours on her candy-covered volcano project, that story became painfully true not only for her, but for her poor dog, Reggie.

The 2-year-old yellow Labrador got ahold of Payton's hard work for her eighth grade science class, which had been assembled with more than 50 straight pins holding all the candy pieces securely in place.

"She had chocolate as the mountain and used Twizzlers for lava coming out, with blue M&Ms for water," Payton's mother, Kara Moody, told GoodMorningAmerica.com. "She used the pins because I didn't want the hot glue gun around her younger brother."

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While most of the family was away at their son's football game on Oct. 20, Reggie had managed to knock the completed project off the top of Payton's desk, proceeding to eat "every last little bit," according to Moody, 46, which was comprised of "pretty much the whole box of pins."

Once they realized what had happened, the family immediately rushed Reggie to the Veterinary Specialty and Emergency Hospital to undergo emergency surgery to deal with the dangerous amount of straight pins and chocolate, which is also toxic for dogs.

Courtesy VRCC

"I have seen dogs eat pins before," the operating surgeon, Dr. Brian Van Vechten, explained. "I had a dog that ate a whole 40 or 50 paper clips before, but there wasn't an underlying reason for that one."

"This one," however, he added, "was just wolfing down the chocolate, and the pins came along secondarily."

The X-rays showed Reggie ingested more than 50 metal straight pins, the majority of which were able to be removed with an endoscopy.

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"They were able to take most of the pins out with an endoscopy, but there were still six or so in the stomach, so I was called to take the remaining pins out through surgery," Van Vechten said.

Fortunately, the dog made a full recovery after a two-day stay at the veterinarian's office, although the family says he still hasn't learned his lesson.

"[Payton] remade it with the hot glue gun so there'd be no pins, and he still went after one," said Moody. "He didn't learn his lesson at all."

Despite the first candy-filled calamity, Payton still managed to earn an "A" on the second version of her volcano project.

ABC News' Cho Park contributed to this report.