It's a pretty straight forward process importing a dog into Hong-Kong. Canada is a group two country so there are no special problems and no quarantine providing you comply fully with the import permit requirements. These are straight forward, the dog needs the correct vaccinations and the correct type of micro chip etc., all the info can be found on
http://www.afcd.gov.hk/english/quara..._ipab_idc.html just drag and drop it into your browser.
The best is to give then a call and chat to someone who will take you through step by step. The first will be getting an import license from the department, a few days wait is all it takes.
I recently imported a dog myself and had no problems as far as paper work etc, in fact you only need the import licence, valid for three months I think and the required veterinary certs from the other end all filled in neatly and the rest is basically getting the dog onto the plane safely the other end.
The only hiccup we encountered was that the puppy arrived after an 18hour flight and it was lunch time here. Yes believe it. The puppy had to sit for two hours waiting for the jerk to finish his dinner before we could get it out of its little hut, this after we had phoned the airport state vet as is required, a week before arrival and then again the day before.
This wouldn't have been any different had we used an agency, but there really is no real need for one, as long as you have someone competent at the other end organising shots and a crate etc.
Well before your dog leaves you submit the documentation this end and they give it the once over and tell you if there are any problems or things you need to do. Basically they are very helpful and make sure you get it right well before you even book the flight. A direct flight is always the best for the dog.
Good luck