Alleged teenage cat-killer refused bail

A Sydney teenager accused of repeatedly stabbing a cat before throwing it off a balcony had obtained the animal from the RSPCA a week earlier.

Celina Paige Shead, 19, is charged with two offences related to animal torture and cruelty.

She faced Manly Local Court on Friday when magistrate Miranda Moody refused her bail due to concerns about the safety of other animals.

Most people would be "pretty horrified" at the manner in which Shead allegedly killed and disposed of the cat, she said.

The magistrate also noted Shead had been sentenced only last week to an intensive corrections orders for other matters.

The body of the cat, which had allegedly been stabbed 20 times, was found near Shead's northern beaches home on Wednesday morning.

The teenager's lawyer, Luke Noonan, said her father, who could not be present because of his employment, told him she was diagnosed a year ago with a borderline personality disorder.

The court was told Shead obtained the cat - and another which has since been placed in the care of the RSPCA - from the animal welfare organisation on October 15.

She is due back in court on November 8.