Greek yogurt, blueberries, banana, and strawberries together in a blender; cover with a lid and blend until smooth.
Place the dog treat silicone trays on a baking sheet then spoon the mixture into molds or ice cube trays.
Place in the freezer for 2 hours, or until frozen solid. Transfer the frozen berry-banana dog treats to an airtight container and store them in the freezer. Enjoy.