http://www.ontla.on.ca/documents/Bil...on1/b132_e.htm

It seems that pit bulls have been banned in Ontario, and that if you have them they must be immediately spayed or neutered and kept muzzled in public and private, and that if the dog attacks a person or animal the owner will be held responsible in both criminal and civil court. The police can also seize (with warrant) pit bulls in the interest of public safety. In fact if you live in Ontario it is now illegal to acquire a pit bull:

Pit bull ban
6. Except as permitted by this Act or the regulations, no person shall,
(a) own a pit bull;
(b) breed a pit bull;
(c) transfer a pit bull, whether by sale, gift or otherwise;
(d) abandon a pit bull other than to a pound operated by or on behalf of a municipality, Ontario or a designated body;
(e) allow a pit bull in his or her possession to stray;
(f) import a pit bull into Ontario; or
(g) train a pit bull for fighting.