Okay, here's my 2 cents on this: all dogs go thru stages of soft poops, runny poops, hard poops, no poops...just like us humans. I'm wondering if maybe you are being a little too analytical about Bogey's poops? It sounds like you have ruled out the parasite and are now focusing on the food so that's good. But I wouldn't be chasing every poop symptom with a different food approach. I'm wondering if maybe Bogey feels your anxiety about his poops and food, and the little guy is feeling a little anxiety and nervousness as well, and this manifests thru his tummy.