Between 1990 and 2007, of the 28 fatal dog incidents in Canada, Pitbulls were confirmed responsible for one fatal attack. Rottweilers were responsible for three, huskies and "sled dogs" a combined 7, and "other", mixed-breed, and non-reported a combined 20.
http://www.ncbi.nlm.nih.gov/pmc/arti...t1-cvj49pg577/
From the article: number may add up to greater than a total of 28 (or respective subtotal) because dogs from more than 1 category were implicated in some attacks
Given that the Canadian Safety Council estimates that 460,000 Canadians are bitten by dogs each year, 28 fatal dog incidents in 17 years means 0.00035% of dog-bite incidents are fatal or, more specifically, it is not a problem.
Furthermore, there is no demonstrable relationship between breed-bans, or even leash-laws, and dog-bites and fatal dog-attacks. All studies involving breeds responsible for dog-bites are fraught with sources of error (note the huge number of other, mixed-breed, and non-reported above).
There is, however, a direct correlation between gun-control and a reduction in gun-related injuries and fatalities.
While it seems like a logical argument to compare 'dangerous breed' laws to gun-control laws, it is not supported by evidence. This is one of the reasons breed bans are opposed by pretty much every dog-related and/or animal-welfare organization in the developed world.