They have "dog repellent" available for Canadians. This product can be ordered online and it comes in keychain versions too.
(below taken from wikipedia)
In Canada
In Canada all products with a label containing the words pepper spray, mace, etc, or otherwise originally produced for use on humans are classified as a prohibited weapon[28]. Only Peace Officers, and individuals/corporations who have special government permits may legally carry or possess pepper spray. Any similar canister with the labels reading "dog spray" and/or "bear spray" is regulated under the Pest Control Products Act - while legal to be carried by anyone, it is against the law if its use causes 'a risk of imminent death or serious bodily harm to another person' or harming the environment and carries a penalty up to a fine of $500,000 and jail time of maximum 3 years[29]. Of course, the legality of using spray intended for animal deterent on a person would be determined in court on a case-by-case basis.