Some links to start with
If you type in the words mare, stallion or gelding in the box and continue on from there you will get information on what is required to import an equine of chosen gender.
If you are comfortable handling paperwork yourself it seems that airhorse.dk offers that option in their quote requests.
If you decide to ship your horse in to US and then transport by road to Canada one company that does this in the eastern end of Canada is http://www.inthorse.com/
More information coming soon once the quarantine requirements have been defined and a few quote requests have arrived, just to give the general idea on shipping a horse to Canada.