Try to locate the smaller bag, as your pup may not like Wellness and it takes a LONG time to go through a 12lb bag and food can get stale. You can also try emailing them for samples that are free at:
WELLNESSŪ - Healthy Dog and Cat Food You can also go the sticky at the top of the Health and Diet Section here on YorkieTalk and see all the websites you can ask samples from. I hope your pup likes Wellness...mine was not a fan