For some sobering numbers, internationals should go here:
http://premedusa.blogspot.com/2014/06/US-Medical-Schools-for-Internationals-Updated.html
Looking at the data listed on the page – 115 internationals matriculated into US allopathic med schools (MD and MD/PhD) in 2014 and 52 of the internationals matriculating were at med schools that only consider Canadian applicants. So at a minimum, 45% of the internationals matriculating into US med schools were Canadian citizens.