You may be able to purchase it through Port Credit Pet Centre in Toronto, but it is not CSA approved because you have to wire it yourself so it is not readily available in Canada. It is not a problem to get it shipped in from suppliers in the US though.
An alternative that Port Credit does stock is heat rope, a single strand of heated rope that comes in various lengths and is pre-wired with a pug-in for the rope. I use it on a rack system and two strands heat 40 shoebox tubs very effectively.
mary v.