NEW YORK (Reuters) - The New York City shelter housing 280 pets displaced by Superstorm Sandy must shut down and, with nearly half the animals still unclaimed, cannot rule out euthanizing any left behind.

An uncertain future lies ahead for 52 cats and 84 dogs who remain in the Brooklyn emergency boarding facility run by the American Society for the Prevention of Cruelty to Animals, spokeswoman Kelly Krause said on Thursday.

They are among 280 pets sheltered since November, after the New York City area was devastated by the late October storm.

The facility was originally scheduled to close on December 17, but the volume of unclaimed pets prompted the ASPCA to extend its deadline into January.

What will happen to those pets whose owners fail to return is unclear. The ASPCA is looking into placing the unclaimed pets in foster homes or shelters if their owners are unreachable or unable to take them back, although no hard deadline has been given to owners, said Krause.

Following Hurricane Katrina, many similarly unclaimed pets were put up for adoption and placed in caring homes, only to have their owners surface months later and seek to get them back.

“We are still caring for the displaced pets at our emergency boarding facility, but we’re also planning the next step, which is to find homes for unclaimed animals as we start to demobilize our operation,” Tim Rickey, senior director of ASPCA Field Investigations and Response, said in a statement.

Most of the owners that the ASPCA has identified live in temporary housing or with family and friends, environments that prevent them from bringing their animals home, Krause said. A majority of the owners who had yet to claim their pets lived in the hard-hit Rockaways neighborhood in Queens.

Many pit bulls and mastiffs, dogs that shelters typically find hard to place given their vicious reputations, were among the unclaimed canines.

It was too early to say whether any of the pets that remain left behind would be put down, Krause said. (Reporting by Peter Rudegeair; Editing by Barbara Goldberg and Sandra Maler)