A friend of mine once did what you're doing - kept adding better and better stuff to her dog's food to get him to eat. After ending up mixing in filet mignon and lobster with the same results (he ate it for a couple of meals then went off it), she had to abandon the effort. That meant going back to feeding dog food without the "better stuff" until he gave in and ate. Of course her dog was a Rottweiler; with a small dog you can afford lobster then move on to truffles.
You might want to try a different kibble. The only dog I had who would not eat well, sometimes leaving some, sometimes not eating at all, stopped the fussing and ate like a Rottie should when I changed kibble. She's kind of a nervous dog and it never occurred to me it could be she just didn't like that particular kibble until she started cleaning up her food every meal the day I changed. For what it's worth, as I remember, it was one of the Fromm brands she wasn't eating well.
I always mixed a little canned in with kibble and added water, but that was mostly because plain kibble looks unappetizing to me. Ask your vet, but it's my understanding a healthy dog won't starve himself, so if your dog is healthy and not a puppy, you could try the standard method of dealing with this kind of behavior: put the food down, give it 15-20 minutes, pick it up and don't offer more food until the next regular mealtime.
If you don't like your vet, find another, but sometimes tests are called for. If they try to push food they sell at you, just say, "I tried that, and he wouldn't eat that either."