He's back to eating. I gave him hamburger/rice bland food Sunday night, and then weaned him back onto kibble. Right now I've been giving him Acana Duck and Pear (the new formula that is potato free) and no raw. I think it was the yams in the Primal that made him so sick. I haven't tried giving him any raw since it all happened, other than giving him bits of stella and chewy's patties as treats.
When I took him to the vet Wednesday I saw a vet I'd never seen before. My normal one had a family emergency so he was not there, and I really didn't like the one I saw. She did examine him closely, but only suggested trying a medication that they never keep in stock. She actually didn't even mention the allergy testing, it was the lady that works the front desk that did.