Ontario
Four years after implementing breed bans in Ontario, Canada in 2005, dog bites were down 32%, from 486 to 329.

Bites in Toronto, Ontario fell sharply, from 71 in 2005 to only six in 2010.
http://banallpitbulls.blogspot.ca/2015/02/the-failed-outcome-of-breed-neutral.html

City data shows that before Ontario banned them nearly a decade ago, pit bulls did more biting per capita than other breeds; but today’s neutered, muzzled pit bulls registered only 13 bites in 2013.
http://www.thestar.com/

Manitoba
Effectiveness of breed-specific legislation in decreasing the incidence of dog-bite injury hospitalisations in people in the Canadian province of Manitoba

http://umanitoba.ca/news/blogs/blog/2012/07/09/does-the-pit-bull-ban-have-teeth/

http://injuryprevention.bmj.com/content/early/2012/06/29/injuryprev-2012-040389.full