Animal origin ingredients
Meats, listed on the label as beef or lamb, refer to skeletal muscle (flesh) and muscular organs, such as the heart, tongue, and diaphragm. Poultry, such as chicken, duck, or turkey, includes flesh and skin, with or without bones. Fish, including whitefish and salmon, refers to the cleaned tissue of whole fish or pieces of fish. 

By-products from mammals include non-rendered (non-heated) parts other than flesh. This can include the lungs, spleen, kidneys, brain, liver, blood, bone, fat, stomach, and intestines. It does not include hair, horns, teeth, and hooves. Poultry by-products are necks, heads, feet, undeveloped eggs, and intestines, but not feathers (except those that may be unavoidably included under accepted processing practices).

Meat, fish, poultry, or by-product meal, preceded by a source, such as “lamb meal,” refers to the process of rendering (heating) and grinding the starter ingredient. This removes most of the moisture and fat and reduces the particle size of the end product.

Meat and bone meal includes rendered mammal tissues and bone, excluding blood, hair, hoof, horn, hide trimmings, manure, and stomach and rumen contents (with the same exception as for feathers).

Other protein sources may include dried egg product without shells, caseinate (milk solids), and whey, the fluid portion of milk.

Grain ingredients

Barley must be at least 80 percent barley but may include up to 3 percent damaged grain, 6 percent foreign material, and 20 percent other grains.

Brewer’s rice is the dried residue resulting from the manufacture of malted grain or beer. It may contain up to 3 percent hops (the flowers of the hop vine are used in beer-making).

Gluten of any grain is what’s left after removal of bran, germ, and starch.

Ground corn includes the kernels and cobs, while ground whole grains include the bran, germ, starch, gluten, and oils. Soybean meal is a by-product from soybeans after extraction of the oil.

Fat and oil ingredients

Flaxseed or linseed meal and fish oil are sources of omega fatty acids.
Vegetable oils, such as corn, canola, and sunflower, contain more fatty acids than animal fats and tallow.

Fiber sources

Beet pulp is the dried residue from sugar beets, with or without the sugar removed.

Pomace is the pulp of fruits and vegetables. Peanut and soybean hulls (pure cellulose that’s indigestible fiber) increase the bulk of the finished product or dilute the calories in a reduced-calorie food. Bran of any grain is the outer coating of the kernel.

Mill-runs (middlings) of any grain are a by-product of milling, mostly hulls.

Additives

Digest is hydrolyzed (broken-down) animal tissue sprayed onto the outside of dry dog food for added flavor. Corn syrup also increases palatability with a sweet taste and acts as a preservative, inhibiting bacteria.

Gums, including guar, xanthan, carageenan, and pectin are plant extracts, used as stabilizers or thickeners. BHA, BHT, and ethoxyquin are synthetic preservatives.

Tocopherols and ascorbate are vitamin E and vitamin C, used as natural preservatives.
Other possible additives include coloring agents, glucosamine and chondroitin (joint health supplements), probiotics (bacteria or yeast to aid digestion) and L-carnitine, which may help with fat metabolism.

Susan Bertram, DVM, is a veterinarian in Bend, Ore.