Toronto ? Ontario on Monday became the first province in Canada to ban the pit bull in the wake of vicious attacks by the dogs, but defiant owners have already challenged the law.

The measure makes it illegal to breed pit bulls or bring the dogs into the province. Those already in Ontario will be allowed to stay on a restricted basis, provided they’re spayed, and leashed and muzzled in public.

There’s a 60-day grace period, until Oct. 28, for owners to comply with the law. Any pit bull born after that will have to be shipped out of the province, sent to a research facility or destroyed.

Owners who violate the law can face up to six months in jail.

A number of serious attacks across the province prompted Attorney General Michael Bryant to make move. In another case, two dogs severely mauled a Toronto man, forcing police to shoot the animals repeatedly to stop the attack.