Law and order came early and often. Patrolman Anthony D'Onofrio struck early and often.

By 9 a.m., he'd given 13 dogs owners summons, and if the dogs of Central Park weren't running scared, they weren't running free, either.

D'Onofrio was a one-man crackdown on the first days of New York state's new public health law, which requires dog owners, in the language of a leadlet distributed by the city, "to pick up after our pets, just as we should pick up after ourselves."

The leaflet, from Mayor Edward Koch and Sanitation Commissioner Anthony Vaccarello, lists helpful hints for those puzzled by how to clean up their dogs' waste.

It's tone is gently encouraging. "Practice makes perfect. Don't be discouraged if you first attempts at scooping seem awkward or distasteful. Remember, with practice, it becomes easier."

A number of dog owners who spotted Vaccarello and four of his sanitation policemen surrounded by TV cameras and reporter on Central Park West were eager to question the city's priorities.

"The muggers, the prostitutes and the bums don't deteriorate in the rain, but this staff will," Liza Manceli said.

Rachel Gallagher argued that other litter laws should be enforced. Human excrement, she said, is a serious problem in Central Park.

Tuppence and Strider, Gallagher's two Basenjis, posed for photographers at the base of a lamppost, while Commissioner Vaccarello climbed above them to affix one of the city's first signs urging compliance with the new law and warning that fines for refusing to clean up after a dog run from $25 to $100.

"I'm here." Vaccarello told a reporter who asked what the purpose of the commissioner's presence might be, "to make people realize the city intends to enforce this law."

Patrolman D'Onofrio has been zealously enforcing the law against letting dogs roam unleased for a long time. Now he has another legal weapon.

"These people hate me," D'Onofrio said with a grin. "They call me the Lone Ranger." A lawyer approached who alleged that D'Onofrio once caught him jogging with his unleashed dog, chased him out of the park and pursued him by motorcycle into his apartment building lobby because the lawyer, Daniel Aharoni, didn't have identification in his jogging shorts.

The Sanitation Department estimates that dogs drop 250,000 pounds on New York every day. "This is a serious problem," Vaccarello said. But the sanitation police have only about 170 patrolmen in the five boroughs. New York police and other auxiliary forces also are empowered to enforce the new law, but their zeal is yet untested.

Sanitation Department spokesman Vito Turso reported owners demonstrating obedience throughout the city yesterday, but said more than 50 summons had been issued, according to incomplete reports.

New York officials intend to announce a tally of dog owners nabbed each day, but the totals will be 24 hours old. The tally is another part of officials' efforts to demonstrate the seriousness of their intention to keep the new law alive rather than follow the example of other cities, which have let it be so ignored that enforcement ends without even a whimper.

One dog owner made clear that she intended to comply with the law whenever she saw an officer nearby and ignore it other times.

A patient violator can also try to outwait a lawman. Only if a dog owner leaves the scene can he or she be given a summons.

Patrolman Frank Brucale described the dance (perhaps destined to become a New York ritual) that he and a violator went through on the Lower East Side yesterday morning.

After several feints, the violator abandoned hope of outlasting Brucale and left the scene. Brucale issued a summons.

"You have to play cat and mouse," Brucale said of his dogged pursuit."