The Essex County Prosecutor's Office said Kisha Curtis pleaded guilty to fourth-degree animal cruelty. She also gave up custody of the dog. Curtis was set to go to trial on Wednesday.
The 29-year-old Irvington resident was accused of tying the pit bull to the railing in her former Newark apartment building, then leaving the state for more than a week in 2011.
The dog - named Patrick by his rescuers when he was brought in around St. Patrick's Day - was found near death in a plastic bag at the bottom of a trash chute. The dog survived and recovered.
Thousands of fans followed Patrick's progress on his Facebook page, and a custody fight over the dog erupted after his much-publicized plight resulted in thousands of letters and donations from around the world.
The dog has been living with a foster family after being cared for initially by the Associated Humane Societies and then Garden State Veterinary Specialists in Tinton Falls, where he was nursed back to health.
State Superior Court Judge Joseph Cassini III will decide who will have permanent custody of Patrick. Cassini plans to issue his order at Curtis' Aug. 29 sentencing, according to the prosecutor's office.
The charge Curtis pleaded to carries up to 18 months in prison, but she may not serve time as a first offender.
Curtis was not accused of placing the dog in the trash chute, but prosecutors said she was responsible for abandoning and starving the dog, resulting in his "torment and torture."
She was previously denied entry into a pre-trial program that could have kept her record clean.