So New York has roughly 1.5 million dogs, licensed and unlicensed.

When he first took the job, dog bites (to humans and to other dogs) and unlicensed and unvaccinated dogs running loose were common.

Lao Er's life is thrown into turmoil when the government in an effort to control rabies, decrees that all unlicensed dogs are to be cast out of the city.

Far from curbing pet ownership, it led to a swelling canine underground of unlicensed and sometimes unvaccinated dogs.

They take Pipi out only at night, in the narrow alleys around their home where many neighbors also take their unlicensed dogs for quick walks.

"We've got about half the town done, the western half, and already, we're picking up a lot of unlicensed dogs," Ms. Cory said.

It means disease-carrying animals such as bats, skunks, - unlicensed dogs - and rats.

The pit bull's owner receives only summonses for having an unlicensed dog and for not keeping it on a leash.

Guillermo Zavala, 33, whose family owns the pit bull, was given summonses for having an unlicensed dog and for not keeping the dog on a leash.

In July, the city announced plans to capture and kill as many unlicensed dogs as the police could hunt down.