A Gwinnett County woman knew her dogs were "vicious" but didn't keep them restrained, allowing them to attack three people in Lawrenceville, a lawsuit says.

Zhongkai Mao, a 77-year-old man severely injured by the dogs, has sued the dogs' owner in Gwinnett County State Court, claiming the woman's negligence led to the dogs attacking him.

A phone number listed for the dogs’ owner was disconnected Thursday.

READ | Loose dogs attack 3 in Gwinnett, leave man mangled 'from head to toe'

MORE | Gwinnett man attacked by dogs could have lost leg, daughter says

Mao was walking home about 5 p.m. on April 2 from Ronald Reagan Park along Five Forks Trickum Road when the two pit bull mixes jumped on him. The dogs bit Mao from "head to toe," causing gaping wounds on his legs, exposing muscle and bone. Mao remains in the hospital 10 days later, with skin grafts planned for next week, said Xiaohong Davis, his daughter.

“We are hoping recovery can start,” she said.

Multiple drivers saw the dogs attacking Mao and stopped to help. Two drivers beat the dogs with a shoe and a baseball bat until they let go of him, a witness said. Mao would likely have lost his left leg if he had not been able to have surgery immediately after the attack, a doctor told Davis.

The dogs attacked two other people that day before returning to their owner’s home. They were surrendered to Gwinnett County Animal Welfare and euthanized. The owner was given six citations but was not charged with any criminal offense.

The owner knew the dogs had bitten someone before the day of the attack, the lawsuit alleges. The dogs — identified in the suit as Scooby and Freddie — were allowed to run free without restraints and they were not prevented from leaving their owner’s property, according to the lawsuit.

The suit asks for damages to cover Mao’s current and future medical expenses. Mao immigrated to the U.S. from China in February to live closer to his daughter and is not insured, she said.

Like Gwinnett County News on Facebook | Follow us on Twitter and Instagram

Stay up to the minute with breaking news on Channel 2 Action News This Morning