At 2 days old, she’s available, no questions asked, to anyone with $700 cash.

“They got protein milk for newborns if you want her now,” said a man who called himself Thomas, holding up the whimpering newborn pit bull to a reporter posing as a potential buyer.

“Better, though, to wait the two weeks,” Thomas added as he sat in his Jamaica, Queens, apartment with the squirming animal, so young her eyes had not yet opened. “Come back, she’ll be ready.“

Thomas is one of the city’s uncounted home breeders of pit bulls, an exploding and sometimes cruel cottage industry centered in the city’s poorer neighborhoods.

Some are put in dog-fighting rings as they get older — and tens of thousands more wind up euthanized in New York City every year thanks to the glut caused by overbreeding, said Craig Fields, founder of the New York Bully Crew, a rescue and educational group based in East Patchogue, LI.

Thomas had two Craigslist ads last week offering newborn males for $500 and females for $700. Of the seven adult pit bulls he had in cages or tied up in the kitchen, two were visibly pregnant.

“I got two more litters coming,” he boasted.

Robert Shapiro, who runs the East Village animal shelter Social Tees, described a problem run amok.

“It’s completely out of control,” Shapiro said. “They sell them in parks, at the handball courts, on the Coney Island Boardwalk.”

Just last week, Shapiro photographed a litter of sad-looking brown and white pit bull puppies being sold out of a cage with no water on the sweltering boardwalk for $250 each.

Nini, Thomas’ mother dog, is a retired fighter, a friend of his said.

“Man, that dog is a beast,” said the pal, who gave his name as “C.”

“Them dogs back there try to kill each other,” he said of Thomas’ pack. “And they not going to stop until they kill each other.”

It’s illegal in New York state for home breeders to sell more than 25 puppies a year directly to the public without a license.

After the reporter identified himself to Thomas, the man said not all of the dogs were his and that he hadn’t sold any yet this year. He called himself a dog-lover.

“I don’t raise dogs to fight them,’’ he added.

The state Department of Agriculture & Markets has only 14 animal-health inspectors policing livestock auctions, pet shops, animal shelters and home breeders in all of New York, according to Bill Ketzer, the ASPCA’s legislative director for the Northeast region.

In February, New York City passed its own ban on selling more than 25 puppies a year, but enforcement personnel are not yet in place.

“It’s going to take some time to ramp up into the mandate,” Ketzer said.