LYNN – A pit bull terrier that savagely mauled a Lynn great-grandmother earlier this week was euthanized Friday and will be tested for rabies, city officials said.Vincent Phelan, an attorney in the city’s Law Department, said the dog’s owner signed a consent order to have the animal put down so that it can be tested and perhaps alleviate fears for the victim, 76-year-old Margaret Murphy of Eastern Avenue.Shortly after the dog attacked the woman Wednesday afternoon, its owner, Andre Carrisquillo, 23, of Lynn, could not be found. The young man’s mother, Carmen Santana Carrisquillo, a tenant of the 26 Mall St. apartment where the incident occurred, declined to offer information to police about the animal, her son or his whereabouts.”I was able to obtain from the owner a consent order to euthanize this pit bull. This is the most expeditious way so that the victim won’t have to undergo a series of rabies shots or other testing,” Phelan said Friday. “We need to determine whether the dog was rabid or not.”The animal has been taken to the state lab in Boston’s Jamaica Plain section where the test results are expected in one to three days, said Kevin Farnsworth, the city’s animal control officer.Gathering the information and identifying the dog owner was a collaborative effort by the animal control officers, the building landlord, the Parking Department and, ultimately, Carrisquillo, he said.”We want to make this come about very quickly and to assist Margaret Murphy. Everyone hopes she is doing well and will not have to be put through any unnecessary testing or other procedures,” the attorney said.The consent by Carrisquillo came only hours after Farnsworth opened a criminal investigation into the attack.Farnsworth said the apartment tenant was uncooperative, as was the dog owner. “We had asked the tenant to sign papers allowing us to euthanize the dog so that it could be tested for rabies, but that didn’t happen and put us between a rock and a hard place,” he said.Farnsworth requested assistance from the city’s Law Department to get the legal process into motion.”We couldn’t find the kid who supposedly owns the dog, so we took action against the tenant because she was the keeper of the dog at the time of the attack,” Farnsworth said. “It happened on her property.”While authorities searched for the dog owner, Murphy remained at her home, stitched and bandaged, awaiting word on whether the dog was rabid. Michael Kairevich, the assistant city dog officer, snared the animal at the scene of the attack and brought it to the North Shore Animal Hospital, where it was quarantined.Murphy had hoped to visit her great grandson, Antonio, at the Mall Street apartment, when she was bitten repeatedly. Taken by ambulance to Union Hospital, she required dozens of stitches to close the wounds. The dog’s teeth tore flesh from her face, arms and legs.According to Murphy, she knocked on the apartment door, which was ajar. As the door opened, the dog lunged and pinned her to the hallway floor, biting and slashing until others pulled it off. The apartment tenants told police Murphy did not knock and entered the apartment unannounced, prompting the dog to attack.