Britney Spears' tiny puppy is fighting for her life.

The former 'The X Factor' judge - who announced her split from fiance Jason Trawick on Friday (12.01.13) because he reportedly didn't want to have any children with her - is said to have racked up huge medical bills for her sick teacup Yorkie, Hannah, who is in hospital for the third time.

A source told gossip website that the 'Scream & Shout' singer's first brought the tiny dog to the vet in late November, after she ''found Hannah listless, eyes half shut, not responding to voices, not eating, and having trouble breathing.''

The 31-year-old star bought the dog for $1,800 from Barkworks store in Thousand Oaks, California and first introduced her to her fans via Twitter in November.

The source said that the pup had been back in an animal treatment clinic since January 3, where she underwent tests for liver function and was being monitored for having fluid in her lungs and an erratic temperature, but Britney brought her home late on Friday.

The source said: ''Her condition remains unstable and if it were not for Britney's money and ability to pay the vet bills, Hannah would be dead by now.''

News of her pet's life threatening condition comes just days after the singer announced she had ended her year-long engagement with Hollywood agent Jason. She has now reportedly returned her $90,000 3.5-carat engagement ring.

She also confirmed that she would not be returning to the judging panel on 'The X Factor' USA this year, after recently completing her first season.

According to gossip website, Britney has now ended her contract with talent and literary agency WME and has signed a new agreement CAA.