I would like to change our puppy over to a grain free food. He is a 9 month old papillon and weighs a little over 8 pounds. I have done alot of reading and narrowed it down to Acana or TOTW. I am interested in hearing your thoughts on these two and if you have a preference? I know there is a significant cost factor between the two, but since he eats such a small amount of food it is really not an issue. Thanks for your input.