A severely malnourished pitbull endured months of torture that included having its limbs pulled apart in a medieval-style “drawing,” the vet who performed the dog’s necropsy told the Herald today as authorities plead with the public to help them find the “sadistic” person responsible.

A shaken Dr. Martha Smith-Blackmore of the Animal Rescue League said the fate of the brindle-colored pit cops named “Puppy Doe” before she was euthanized is “unquestionably … hands down” the worst case of animal abuse she has ever seen.

“She was a rack of beaten bones,” Smith-Blackmore said. “Her joints were pulled apart like Medieval times. She was beaten, stabbed, burned over weeks to months and maybe her whole life. And could not walk. When I saw how vulnerable she was and I understood immediately the duration of her suffering, my heart collapsed.”

Smith-Blackmore said “Puppy Doe,” who was discovered by a passer-by Aug. 31 abandoned in woods near the Whitwell Street playground in Quincy, endured having a wrist, ankle and elbow separated from their joints and a leg bone virtually broken in half from being drawn “over and over and over. It’s a very intimate form of violence.

“I don’t know how they did it, but the force was tremendous,” said Smith-Blackmore, who had to step away from the necropsy “in order to come back to it.”

Mercifully, Smith-Blackmore found no evidence of sexual abuse, which she said is not uncommon in animal abuse cases.

“The last thing we can give her is justice,” she said. “We have to weep, because if we don’t weep we become numb.”

Authorities, meanwhile, are pleading with the public to help them find the “sadistic” tormentor who starved and mutilated the dog, saying they’re worried the person may have harmed other animals or even people.

“We need anyone who knows who owned and abused this dog to contact authorities,” Norfolk District Attorney Michael Morrissey said. “The injuries cataloged in the post-mortem examination are grotesque and indicate consistent starvation and abuse over an extended period of time.

“It is highly unlikely that this level of sadistic cruelty could be shown to one animal and not be part of a pattern involving other animals or perhaps vulnerable people,” he said. “We need to ?nd the person who did this and see what else they are doing.”

Puppy Doe weighed 18 pounds — less than half the healthy weight for a female pit between the ages of 1 and 2 — and had a serpent-like split in her tongue, apparently from a crude cutting procedure. The dog also had been stabbed in the eye days before being found, Smith-Blackmore said. She said the dog had calloused bone from repeated blows to the head, and the tops of her vertebrae were smashed from her back being beaten — possibly with a board or baseball bat, she said.

The woman who rescued Puppy Doe, and the police she reached out to for help, mistakenly thought she had been hit by a car.

Smith-Blackmore said Puppy Doe was euthanized hours later by veterinarians at VCA South Shore Animal Hospital in Weymouth.

“The determination was made that this dog would never live a normal life free of pain,” Smith-Blackmore said.

She said Puppy Doe was described to her as “sweet and submissive.” She still had a belly full of kibble when she died.

“She enjoyed a big meal before she went to heaven,” Smith-Blackmore said. “Within hours of being found she had pain medication, food and love. She experienced some tenderness and some care at the end of her life.”

Lending her own appeal for help, Smith-Blackmore said, “If you know anything, please call. Just please call. We really, really desperately need to know who did this. They need help.”

Anyone with information about the dog is urged to call the Animal Rescue League of Boston’s Law Enforcement Department at 617-226-5610, email them at cruelty@arlboston.org, or call Quincy Police Det. Thomas Pepdjonovich at 617-745-5774.