Hi CW,
Keep in mind that just because the vet hasn’t found anything doesn’t mean it isn’t there. My little guy had GI problems that started with not eating well and he dropped weight because of it. He would vomit occasionally and have loose stool. Initial testing, blood work and radiographs, was normal..kept looking, his ultrasound revealed abnormalities. We got resolution with diet from vet….after trying home cooking and limited OTC diets. He is on RC venison and potato. If your dog does respond to ZD I’d keep him on for awhile as in months before I tried something else.
