My Leila is a picky eater as well. She prefers "human" food, particularly chicken. At the vet's the other day for an issue, I asked about getting her back onto kibble since I'd tried everything. He told me about a "ground up liver powder" that you shake on their food, told me it worked for his picky eater. I haven't checked around here, but googled it and found a website to order a sample. Will give it a try. Might be worth looking into
He also told me not to worry, dogs will not starve themselves...good luck!