The 2005 Dog Owners Liability Act forbids people from owning, breeding, transferring, importing or abandoning pit bulls, a breed with a reputation for aggressiveness and biting, Canadian Broadcasting Corp. News reported Friday.
Pit bull owners whose dogs were born prior to the ban are allowed to keep them, but they must be on a leash and be muzzled.
Member of Parliament Cheri DiNovo of the New Democratic Party said she would introduce a bill to repeal the pit bull ban.
"We know that breed-specific legislation doesn't work," she said. "What we have now is cruel. It's resulting in the death of family pets."
Dog owner Angie Laurusaitis, whose dog Daisy was born before the ban took effect, said she wants the law scrapped.
"These are good dogs, they shouldn't be discriminated because of how they look [and] they shouldn't be muzzled," she said.
Ontario Attorney General John Gerretsen defended the ban and said it has led to a reduction in bites.
"It's had an effect on protecting the people of Ontario," he said.
In April 2010, the Toronto Humane Society said the ban had not reduced the number of dog bites province by much, the Toronto Star reported at the time. The animal protection group said there were 5,714 bites reported in 2004 and there were 5,428 in 2005, 5,360 in 2006, 5,492 in 2007, 5,463 in 2008 and 5,345 in 2009, the Canadian network CTV said.