I spoke to some Tibbie owners & some of the good breeders.
First, the Tibbie owners all said that when they first open a packet of dry dog food, their dogs are more likely to eat it. After a week or so, the dry food seems to smell or taste 'stale' to the dog...& that's when it starts getting picky.
So people do things to keep the dry food as fresh as possible. They buy it in the smallest packets so it gets used up more quickly. As soon as they buy a new packet, they transfer the contents to air-tight jars with screw-top lids. They store the jars in a dry, cool place.
One of the very top breeders said that dogs are more geared than humans to not eat...so she said not to get too anxious about the pickiness. She said to put down the bowl of dry food for the dog. If it is not touched after 10 minutes, take it up. Then later put it down again for 10 minutes & take it up again if not eaten. She said that a valuable import Tibbie she had stuck this out for a week & then he began to eat normally...
Another breeder said that her Tibbies like dry cat food. She's checked this out with her vet & he said dry cat food was OK....but he said that canned cat food was not OK for dogs. The canned food contains a lot of oil & has a too high fat content for dogs. This breeder uses Whiskas dry cat food with her Tibbies. But she said she also uses Purina One & Eagle Pack.... the varieties with the small-sized kibble.
Hope some of this helps with Zoey. (Tibbies look like Shih-Tzus that have had a haircut.)
Marie