Picky Shetland Sheepdogs Love Purina One
We have two Shetland Sheepdogs named Missy and Toby, with Missy being 4 years old and Toby 2. Currently we feed the dogs Purina One. When they were puppies we fed them Purina Puppychow. We tried several different brands that were suggested by our vet, but neither dog would eat any of them until we tried Purina One, they love it!
Typically we buy our dog food at Wal-mart because it is usually a good price and that's where we buy our food, so it's convenient to buy their food there as well.
I'm not sure about other Shetland Sheepdogs, but Missy and Toby are terribly picky about what they eat - that is with dog food. They will eat ANYTHING you give them from the table, but we try not to do that too often, because then they won't eat their dog food.