You may do a CIPO trademark search on the CIPO database:
http://www.ic.gc.ca/app/opic-cipo/trdmrks/srch/tmSrch.do?lang=eng
and a USPTO trademark search on the USPTO TESS database: http://www.uspto.gov/trademarks-application-process/search-trademark-database
and a global trademark search on the WIPO brand database at: