Some of the symptoms SORT of sound a bit like bloat, but not really, and Yorkies aren't really prone to bloat.
Bloat in Dogs
But maybe the canned EVO is having a part? Evo is significantly higher in protein and fat than Acana (I think protein is like 42% in the kibble). So maybe that's what's not agreeing with him. For some reason, I doubt it's the Acana but every dog is different, esp. if he stopped doing it since eating the i/d food.
I wish I had more advice for you!