As everyone knows, the French love dogs and don't mind what they do on the sidewalk. Starting today, pit bulls are an exception to the dog-loving part.

A new law requires all pit bulls to be sterilized, muzzled, registered at city halls and kept out of public places.

The restrictions, which went into effect today, are the latest in a series of moves by some European countries to control pit bulls, said to be among the most dangerous breeds of dog.

The Netherlands has forbidden the breeding of pit bulls since 1993 and requires them to be sterilized. It expects the breed to be extinct there in two years. The Netherlands also requires an "aggression test" for five other breeds, and dogs that fail must be muzzled, sterilized and kept on a short leash.

Britain enacted controls on pit bulls similar to those in France in 1991.

In France, pit bulls are responsible for relatively few deaths. But they tend to be owned mostly by alienated, low-income young people who raise them for fighting--a bad sign for potential enforcement of the new law.

"In ghettos where the police don't go in already, I don't see why they will go in because of this law," said Paris city councilman Jean-Michel Michaux, a veterinarian.

Officials estimate France has 20,000 to 40,000 pit bulls, up from 200 to 300 in 1993.

In theory, violators of the new law face a six-month jail term and a fine of up to $780. But France is a country with many laws no one obeys, and this threatens to become one of them. The police have been given no special training or extra resources to enforce it. According to Gerard Boyer, head of the police union, nine officials will administer the law for all of Paris.

The law also calls for controls on other breeds deemed dangerous, such as the American Staffordshire terrier. Walking a brown and white Staffordshire this morning, one Parisian knew all about the new law. "Yes, he's supposed to wear a muzzle, though it doesn't have to be on," the owner said cheerfully. There was no muzzle in sight.

Pit bull fans claim the breed had been unfairly discriminated against. In fact, according to statistics cited in the French press, of the 15 deaths caused by dogs in France since 1989, nine were from German shepherds and none from dogs identified as pit bulls. German shepherds are not on French lists of dangerous dogs.

"If the poodle of my concierge bites someone, it's not classified as a dangerous dog. But if a pit bull does nothing, it's a dangerous dog," said Serge Pautot, a lawyer for the association of pit bull owners.