A topper is a flavor or texture add-on (gravies, freeze-dried mixers, broths, chunks) intended to be added to a complete-and-balanced base diet — not used alone. AAFCO requires non-complete products to carry the statement "intended for intermittent or supplemental feeding only" near the ingredient list. Toppers are useful for picky eaters, hydration (especially in cats), and to make dry food more palatable for senior pets, but feeding a topper as a sole diet would create nutrient imbalances over time. KibbleWatcher tracks topper as a separate product category and exempts toppers from the AAFCO compliance gate.