What pet-food labels really mean

Pet food is regulated at the national level by the Food and Drug Administration's Center for Veterinary Medicine. Much of what you see on pet-food labels is defined by the American Association of Feed Control Officials (AAFCO), which sets standards for pet-food manufacturing.

The 95 percent rule

(Beef for Dogs). Named ingredient(s) must account for at least 95 percent of the product by weight.

Dinner

Also Entreé Formula, Nuggets, Platter, Recipe (Chicken and Salmon Dinner for Cats). The named ingredients together must make up at least 25 percent of the product by weight, not counting water. Each individual food must make up at least 3 percent.

"With …"

(Gourmet Fillets with Turkey for Dogs). Contains 3 percent or more of the named ingredient.

Flavor

(Beef flavor). No specific percentage required, but the product must contain enough of the food to impart the claimed flavor, or another substance that tastes like it (beef stock, for instance).

Guaranteed analysis

Mandatory guarantee that the food contains the labeled percentages of crude protein, fat, fiber, and moisture.

Light, lite, low-calorie

Meets AAFCO limits for a reduced-calorie diet for overweight dogs and cats. "Lean" and "low-fat" have a similar meaning for fat.

Natural

Technically, food has few or no synthetic ingredients. But the claim is loosely defined.

Grain-free

Protein in the product comes from nongrain sources (perhaps for people who want pets to eat more animal protein). It's not clear whether there's any benefit to a diet high in animal protein.