Mr. Contino, a slight, articulate man living on a pension, roams the vacant lots, windswept beaches and rubbage-strewn alleys and parks of Brooklyn, trying to save the lives of abandoned animals. Some of the animals stay their whole lives, but most go onto new adoptive owners.

At 48, he is an admittedly obsessed man. His wife left him after just four months of marriage many years ago. "She said it was a choice between her and the dogs," he said with a tight smile. "The dogs miss her very much."

Mr. Contino’s mission is one he shares with hundreds, maybe thousands, of New Yorkers who are concerned about homeless animals, a population of strays that the rescuers say is surging and whose fate is as uncertain as the next cold snap. He is part of what amounts to an animal underground railroad with many strata – the actual rescuers, the people who give them money, veterinarians who provide greatly reduced rates, people who act as foster owners for short periods, and those who run shelters outside the city to house the perennial oversupply.

At Mr. Contino’s level, it is a controversial undertaking. Rescuers often violate apartment leases by keeping animals; neighbors sometimes complain mightily and the untidy can violate the health code. Moreover, this is clearly a form of vigilantism undertaken by righteous renegades brazenly eager to take matters into their own hands.

But it is an undertaking that is being given increasing attention right now, at what is a dynamic, perhaps decisive moment for the city’s animal control policy, an effort that began in the early 19th century when roving packs of often disease-ridden dogs spurred the city to begin catching strays.

The American Society for the Prevention of Cruelty to Animals took over the task in 1894 but in 1993 asked to be relieved of the job, in part because its contract did not pay enough to allow it to provide animal care beyond killing most of the animals, around 40,000 a year. So the city created a new nonprofit agency, to be overseen by a board of city government officials. It took over on Jan. 1.

The new agency, the Center for Animal Care and Control, promises to reduce the killing by increasing adoptions. In a break with the past, it says it is eager to work with the informal rescue network. Amazingly, there is the beginning of a dialogue.

"Every day, I’m more and more excited," said Martin B. Kurtz, the executive director of the new center, who says he is reaching out to the rescuers and other animal activists. "I need their ideas."

But the army of unofficial rescuers is not about to step aside. The rescuers see the new agency, the Center for Animal Care and Control, as an extension of the past, in part because it hired most of its staff from the society, uses its buildings and hired as its director the city official who oversaw the A.S.P.C.A. They insist the city has no space to house animals, insufficient money to launch an aggressive adoption program and no will to end euthanasia.

Accordingly, the rescuers are accelerating their efforts to catch strays, of which they claim to have captured at least 12,000 last year.

PICKING UP STRAY ANIMALS IS NOT FOR EVERYONE

The officially sanctioned Center of Animal Care and Control, while carefully commending the politically vocal rescuers, warns that inexperienced people should not pick up strays because they might be bitten. It advises people who find a homeless animal to call the center at (718) 649-8600. It says its staff is fully trained. Center officials eagerly offer a handful of letters from satisfied callers to prove the point.

"Your organization came to the rescue," Allison Mandel of Bayside, Queens, wrote about a rescued kitten.

Roger Caras, president of the A.S.P.C.A., agrees that from the viewpoint of logistics, the rescuers’ skepticism may be on target. He said nearly three-quarters of the animals arrive in a bad health, many near death, and must be regularly removed from spaces that could be used by more adoptable animals.

"For the vast majority of these animals, there is nothing else you can do," he said.

The rescuer community is hard to define, extending across all income levels. Most confine themselves to picking up the occasional stray, but some rescue hundreds of animals year after year. Most say they do it out of simple caring; some admit to craving a sense of mission, some openly hanker for surrogate children.

Some belong to scores of small organizations, while others operate individually. They range from a Staten Island woman who recently became a rescuer and spent $190 for medical care for her seventh cat, to a Brooklyn activist who returns sterilized wild cats to their old territory, to a Queens man specializing in injured street pigeons to a Bronx couple pretty sure they currently have 45 cats and 10 dogs.

There is an undeniable purity to their motives. "Animals are totally unresponsible for any of their suffering," said Sandra Lewis, the New York director of Friends of Animals, who first became involved in animal issues by rescuing one dog. "Everybody can extend a helping hand to a dog in a gutter or a cat tossed in a dumpster."

City officials say there is nothing illegal about rescuing and housing stray animals, as long as the rescuers license them, as Mr. Contino routinely does. However, uncleanliness, excessive noise or odors or parasites can be health violations.

The issue recently came to a head in cases of the Upper East Side. On 77th Street near Fifth Avenue, a wealthy homeowner opens the upper floors of his town house to flocks of pigeons and other wild birds, activity that angry neighbors say attract rodents. On East 89th Street, a condominium has gone to court to stop one of the residents from housing dozens of cats which the suit claims are odoriferous.

United Action for Animals, a local group that aids rescuers with grants for food and medicine, estimates that at least 12,000 perhaps as many as 20,000 animals are rescued each year. "On almost every block, there is somebody who tries to do it," said Julie Van Ness, the group’s president.

But animal rescue is something many adherents decline to advertise. One reason is that some are violating their no pets leases. There is also the fear that were their whereabouts known, they would be immediately deluged with more strays than they can handle. They also realize they are regarded as more than mildly eccentric.

Mr. Contino says neighbors call him "wacko" or "the dog man." He answers the phone, "Hello, the nut house."

Mental health experts say that people who collect animals are not necessarily crazy. "Not only are pets pleasant, but they are actually therapeutic," said Bruce Rubenstein, a psychiatrist at New York University Medical Center. "Where you draw the line is when activity with animals completely replaces activity with other human beings."

"It becomes a mission in life," said A. Hilfer, a psychologist at Maimonides Medical Center in Brooklyn. "People find a place for themselves in society."

GUITARS, STOCK CARS AND STRAY-CAT BLUES

Mr. Contino grew up in Bay Ridge, Brooklyn, and never had a dog. He graduated from Lafayette High School and joined the Army when he was 17. He then did a variety of jobs, including driving trucks and a cab. He became a line repairman for the phone company, a job he held until he was disabled by a back injury.

He had many interests and not a few passions. He played bass guitar for a band, something he still does occasionally. His most impressive piece of furniture is a hulking Wurlitzer jukebox stuffed with tunes. Several expensive-looking electric guitars sit on chairs or couches.

His walls are decorated with pictures of stock cars, not animals. He has owned several and won a number of races. He sold his last for $7,500 to buy the van he uses to rescue dogs.

"I used to be not a bad car driver," he said. "Whatever I’ve set out to do, I’ve pretty much done. And that makes you feel good about yourself. But nothing I’ve ever done in my life compares with taking an animal off the street."

For Mr. Contino, the passion began when he happened upon a mongrel with a broken pelvis. He had never owned a pet and was transformed by the animal named Rusty. "The love you get from an animal must be repaid to another," became his credo.

This parallels the experience other rescuers have had. Linda Carapella, a Brooklyn accountant, never had a pet in her life until at age 30 she found a sick cat. She went on to found Kings Highway Cat Rescue, which aids hundreds of stray cats a year. Among other things, it builds shelters for untamable felines after sterilizing them, rents whole apartments solely to house scores of cats, and sends terminally ill animals to a cat hospice in Pennsylvania.

"You pick up one cat, and you can’t help wondering what’s happening to all the rest," she says. "What’s happening is that more and more cats are being abandoned on the streets."

Mr. Contino says each of his animals has its own story, which taken together prove that rescued animals can live fruitful lives. There is Tonto, a shepherd mix whom Mr. Contino found in a vacant lot two Valentine’s Days ago. He had a broken hip, a broken front leg and a bullet hole through his right ear. The veterinarian doubted he would ever walk again, but now he can jump over a fence. Though Mr. Contino’s fervently proclaimed mission is finding new owners for strays, Tonto is welcome to stay forever.

"This dog loves me so much," he says.

There is Precious, also a shepherd mix and one of more than 50 dogs Mr. Contino has rescued from an abandoned and windswept cluster of Coney Island bungalows. He has gone from 47 to 82 pounds but has a bladder disease that has rendered him un-adoptable. "The sweetest, shyest, nicest dog in the whole world," Mr. Contino pronounces.

There is Bingo, a Benji look-alike found in the middle of a street with a hole in his head. A sure bet for adoption, as was Chester, a bowlegged Rottweiler taken by a Bay Ridge couple last week. There are also Spot, the coon hound with no bad habits that was wounded on the Belt Parkway; Tommy, a terrier who barely survived on a fast food outlet’s garbage, and Corie, half Doberman and half Lab and decidedly not up for adoption. "A fear biter," Mr. Contino says sadly. "He could hurt somebody."

Not to mention the cats Mr. Contino feed at 17 separate outside locations each night and has recently begun rescuing. He is in the process of renting an apartment just for cats he finds.

In a way, animal rescuers and their allies form a large support group. Mr. Contino readily admits needing their help. He lives on a pension of $1,300 a month from the phone company. After house payments of $800 a month, existence is something of a financial struggle, particularly since he has filled up a basement rental apartment with dogs in cages.

United Action for Animals gives him periodic financial infusions. One friend, a baker, gives him 40 dozen corn muffins every Saturday. A network of veterinarians reduce bills (say $2 for a $40 office visit), and ultimately forget many. A pizzeria supplies him with dozens of pizas each week, a highly satisfying doggy taste treat, Mr. Contino swears.

"We love dogs and cats, and you wouldn’t believe what John does for these animals," says Louis Barbati, owner of L&B Pizza & Spumoni, at 2725 86th Street, who also occasionally provides pasta and meatballs. "We’ll make Italian dogs out of them," he joked.

But Mr. Contino’s mission is about to be complicated by a development that reflects the tenuousness of the animal underground. He has nine dogs in a large shelter, Pets Alive, that may soon be forced to close in Middletown, N.Y., because of financial problems. Mr. Contino says he currently has no room for them in his Brooklyn home, which he declines to identify even by neighborhood. "I’m sweating it out," he sighs.

It is his overwhelming devotion that most impresses his friends, many of whom are also animal rescuers. Paul Buono, who has himself rescued hundreds of dogs over the years, calls Mr. Contino a one-man army. "He picks up the maimed, the sick, the wounded," he said. "I’ve never seen anybody like him."

CLEANING THE CAGES, VISITING PEOPLE’S HOUSES

Mr. Contino’s routine is rigid. He spends two hours every day cleaning his cages, while his dogs frolic in the backyard. He greets a constant stream of people interested in adopting animals, subjecting them to probing interviews about their life styles. Sometimes he demands to visit their homes. Scott Wittson, a subway repairman, didn’t mind the third-degree; it got him a pet cat.

"Since my last cat died, I haven’t been able to sleep at night. I missed him so much," he said, cuddling a kitten.

Then there are trips to the vet in the afternoon, as well as dog-food runs. Mr. Contino also makes a run to several dozen locations where he leaves food for stray dogs and cats he knows. The idea is to rescue all of them eventually. He says to just feed them would mean cruelly prolonging harsh lives.

The most dramatic part of Mr. Contino’s mission is periodic rescue trips, some the result of calls and some the result of careful plotting. For example, he has for years been rescuing dogs living in some abandoned bungalows behind the Coney Island boardwalk. The number he has caught now exceeds 50, but the three or four still there are very elusive. Friends of Animals recently bought him a new cage for this mission.

Once caught, his first concern is to provide medical care, all vaccinations and most important, to have the animals sterilized. He knows this is short of a real solution, that one male and female cat and their offspring could, in principle, produce 11.6 million cats in nine years. What is needed, he declares, is for the City Council to pass the mandatory spay-neuter bill now before it.

"Otherwise, there’s no hope," he said. "I can pick up animals until I’m 110 and nothing will change."