LYNN – A Lynn great-grandmother seriously mauled by her extended family’s pit bull Wednesday remains under medical watch while the city’s animal control officers search for the owner in hopes of learning whether the dog has been vaccinated against rabies.Margaret Murphy, 76, of Eastern Avenue, drove her car to 26 Mall St. shortly after 3 p.m. to visit her 10-year-old great grandson, Antonio, who lives with his grandmother, Carmen Santana Carrisquillo, and mother Isabelle Santana in apartment No. 10.She knocked repeatedly but nobody answered. The door was ajar. When she opened it, the brown pit bull terrier lunged at her throat, snapping its powerful jaws until her skin was lacerated from head to toe.”The pit bull just knocked me down in the hall and proceeded to bite me. I was shaking like a leaf. I knew I would die unless they got the dog off me,” Murphy said Thursday, bandaged and recuperating in her apartment.”I don’t even know who pulled the dog off me. I was bleeding pretty bad. The skin was hanging off my leg.”Police were called and an ambulance took Murphy to Union Hospital where she received multiple stitches on her face, right arm and leg.Murphy said the dog is owned by Carrisquillo’s son, Andre Carrisquillo, 23, who was in the apartment at the time but lives elsewhere in Lynn.”Andre owns the dog, but his mother isn’t saying because she wants to protect him,” said Murphy, noting that Antonio’s father, Joseph Anderson, is serving time at Middleton Jail for hijacking cars, so the children often go unsupervised at the Mall Street apartment.Michael Kairevich, the assistant animal control officer, snared the pit bull and brought it to the kennels at North Shore Animal Hospital on Neptune Boulevard.”The people helped me get the dog to the truck, but once there it was fighting the whole time,” he said. “I had a heck of a time getting it to the kennel where it has been quarantined.”Kairevich said the male pit bull was not neutered and had no documentation indicating its ownership or history of veterinary care. “We tried to find out who really owns the dog but everybody involved has disappeared,” he said. “The phone numbers we were given were no good so we’ve left messages at the addresses on Mall and Franklin streets. It’s important that we find out if this dog had its rabies shot.”If that vital information cannot be obtained by Friday, Kairevich said he would ask Kevin Farnsworth, the city’s primary animal control officer, to petition the mayor’s office for permission to euthanize the dog so that an autopsy can determine if it’s rabid.”I’d certainly like to know,” said Murphy. “I thought I was done for. Now I’m just waiting and worrying. I’d like to live a few more years.”Police Lt. William Sharpe said officers responding to the scene were told that Andre Carrasquillo was visiting the apartment and brought along the dog when Murphy showed up at the door and entered without knocking.