Originally Posted by aidy

It depends on which airport you fly through E.G. SEA, ATL, MIA DFW, not all though, you would get an ITI label on your bag, meaning that you cant claim in it in the transit but only in Canada, then you would recheck and clear customs.

If your going through an ITI airport, you would just present yourself to immigration, but wont need to deal with the customs on the baggage