I'm not sure how easy it would be for you to match to a residency in Canada-- Canadian grads get 'first dibs' on spots. I'm assuming US grads are treated the same way as any other foreign grads (although among foreign grads, you'd have a huge advantage). If you want to do something like family practice (or something else relatively non-competitive) you'd probably match. I don't know. Find the CaRMS website & read their regulations.
Your citizenship doesn't matter as much as where you got your MD. A Canadian who did their MD in the States would have a similar situation.
However, if you do a residency in the US, it's easy to find work & get licensed in Canada (and eventually get citizenship, if you wanted).
