I have had an almost similar situation. You may want to read my thread.
http://www.yorkietalk.com/forums/yor...i-give-up.html
The only Acana food that I found with a lesser protein content is not available in the U.S. - the Lamb and Apple. The 3 availabe in the U.S. all had high levels of protein. Excellent food though - and my dogs did love it - but unfortunately did not agree with their system. Both Orijen and Acana are great foods - but did not agree with my little guy.
Good luck to you.