Puppies are popping up everywhere amid the rubble left by Hurricane Katrina — and animal welfare workers on the northern Gulf Coast fear it is only the start of a big boom in dog births.

Officials say more than 6,000 pets were saved after Katrina came ashore Aug. 29, and many of them were relocated to homes elsewhere in the country. An unknown number drowned in the floodwaters or died later of injuries.

But thousands of animals remain, running loose in neighborhoods where fences were flattened and many owners are gone.

"I've never seen so many puppies in my life," said Manny Maciel, an animal control officer from New Bedford, Mass., who made two trips to help trap loose dogs and cats in New Orleans and Mississippi.

Earlier this month, Maciel pulled 10 puppies and their mother from beneath a porch in a hard-hit section of Biloxi. He found seven puppies and seven dogs during another shift.

Maciel took all the dogs to the Humane Society of South Mississippi, where a shelter built for 75 animals now holds about 250 dogs and cats, including nearly 50 puppies. The shelter is the largest one on the Mississippi coast.

Workers have yet to see a spike in cat births, but there's no doubt about what dogs have been doing since the hurricane, said Tara High, executive director of the nonprofit group.

"We're beginning to get litters now," High said. "It's a lot of puppies, and it's not puppy season."

Puppies are brought in daily, both by residents and workers like Maciel, who's among eight professional trappers working with the Humane Society of the United States to help capture animals running loose in the hurricane zone. They use harmless wire cages baited with food and lassos to catch dogs and cats.

Maciel and partner Janis Moore drive through mostly abandoned neighborhoods checking reports of stray animals and encouraging pet owners to have their animals spayed or neutered.

Some owners, like Jim Woodfin, are hesitant to part with their pets for fear they'll never see them again. After some discussion, Woodfin, who lives in his van as he repairs a house, agreed to let Maciel and Moore return later for Pooh Bear, his small mixed-breed dog.

"A lot of times it's the only thing they've got," said Moore, of Springfield, Vt., who has made three trapping trips to the coast.

Animals without owners often wind up at the shelter, where workers are overwhelmed despite the trickle of volunteers who help walk dogs and clean up.

About 300 animals had to be euthanized in November at the shelter, High said, but all were too old, sick or aggressive to be adopted. New owners have adopted 378 other dogs and cats.

As many as 75 new animals arrive daily, and there's no immediate end in sight.

"It's frustrating," said High, who has worked every day but Thanksgiving since Katrina. "The phone does not stop ringing."