But the narrow escape wasn't the end of the road for the felines. Their owners took refuge at a hotel that didn't accept cats.

"We sneaked them in and put a 'do not disturb' sign on the door -- pretending we're on our honeymoon," said Warren Sherwood, 56, a systems analyst. "But after three days, they got restless and started meowing."

The couple ended up having to take them to a shelter set up in a gym near their hometown of Long Beach, N.Y.

Entwined with the human costs of the storm, which killed more than 100 people and caused billions of dollars in damage, is another significant toll -- that of the cherished pets that died or were left behind as families fled for their lives, adding in many cases to feelings of displacement and trauma.

Some find it hard to understand why animals are a key concern in disasters engulfing human lives, but owners feel an attachment and responsibility to their pets, said Niki Dawson, director of disaster services for the Humane Society of the United States.

"There's such a strong bond between people and animals that people will put their lives at risk not to leave a pet behind," Dawson said. "So they stay, even when they're told to evacuate, and that puts first responders going back for them at risk."

Owners have recounted tales of a dog swimming through flooded streets and extra food left behind for a tarantula no one was willing to take in.

In New York City and on Long Island, the ASPCA has rescued more than 300 animals and treated or provided supplies to about 13,000, working with government and private animal welfare agencies, said spokeswoman Emily Schneider.

City shelters took in about 400 animals along with their families in the first days after Sandy, Schneider said. There are now more than 100 in shelters with their owners, and a mobile animal medical clinic is cruising decimated neighborhoods in the Rockaway areas of Queens and on Staten Island.

In New Jersey, the Humane Society deployed dozens of first responders using mobile units and boats to bring in about 60 displaced animals each day on the barrier islands hit by the storm.

Two weeks after Sandy made landfall, followed a week later by a nor'easter, search-and-rescue teams were led by Animal Care & Control of NYC, a city-contracted nonprofit responding to hotline calls about pets in distress. Callers are owners forced to leave animals behind or unable to care for them, or people who see them wandering in hard-hit areas.

A Manhattan shelter takes in animals around the clock, hoping for owners to show up. And social media teams scour the Internet for reports of lost pets, helping reunite them with owners.

Rescuing animals is mandatory under federal law, which requires local and state governments to include plans for pets in emergency procedures. Federal Emergency Management Agency funds go toward the welfare of animals in disaster zones.

New York City's human shelters are required to accept pets, and so are taxis and public transportation.

More than 200 dogs, cats and other pets from a devastated area of Long Island are being sheltered in the gymnasium of a community college, set up by the North Shore Animal League America, the nation's largest no-kill rescue and adoption organization. Many, like the Sherwoods' Schwartz and Scooter, belong to owners in nearby shelters and hotels.

"We're ridiculously stressed out; we're freaked out," Warren Sherwood said. "But I'd do anything in the world for these people who are keeping our cats alive."

Also among the pets in the gym is Emma, a Manchester terrier who swam to safety through flooded streets in Freeport on Long Island, while its owners carried their cats above the water, plus some clothes they grabbed at the last minute.

"We lost our house. It's submerged," said Mark Swing, who fled with his girlfriend as the tides rose. "All we got out was our four cats and the dog, except for a few changes of clothes."

The 8-year-old terrier was "a little tired, but fine," said Swing, 48, a contractor who was in a Red Cross shelter.

Cats and dogs weren't the only pets rescued from the storms.

"We're finding chinchillas, guinea pigs, rabbits, reptiles, birds," Dawson said.

There are stories of pets whose fates remain unknown, like gerbils and a tarantula left behind by a teenage boy whose Staten Island home has been deemed uninhabitable.

His aunt in Brooklyn agreed to take in the gerbils, but no one wanted the hairy tarantula. The teen left it behind with lots of food -- in hopes the spider could be retrieved later.

Transport trailers distributed pet food and supplies like crates, leashes and litter from a warehouse in Queens set up days before Sandy descended, said the Humane Society's Schneider. Tons of food donated by manufacturers is being trucked in.

Celebrity chef Rachael Ray is donating $500,000 to the ASPCA to help pets and families struggling to rebound from Sandy. She said her pet food brand, Nutrish, is also shipping 4 tons of wet and dry dog food for Sandy animals, and her Yum-o organization is donating $100,000 to City Harvest and the Food Bank for New York City.

The ASPCA will use the money to lease a building to board Sandy animals until their owners can take care of them.

It will likely be months before any estimates are available as to how many pets might have died or were lost during New York's double storms. And like their owners, many animals that survived won't go home anytime soon.

Dawson said she has seen people stuck in shelters, wearing donated clothing, with no idea when they'll go home. But when they turn to their dog or cat, "their faces light up."

And that, she says, is why animals matter amid a human disaster.