I used the Susan O'Sullivan & Raymond Siegelman book for my exam. Its called 'National Physical Therapy Examination Review and Study Guide' From 'TherapyEd.com'
Its a study guide for the american exam, but I found it covered a lot of the things for the Canadian and in a concise way. It also comes with a CD loaded with practice questions, which again, were very similar to the Canadian. Its pricey, at about $80, but I wouldn't have passes without it. I also used other general respiratory, neuro and msk texts, but the O'Sullivan book was by far the most helpful for a multiple choice exam.
Hope that helps.