What's in Dog Food?
The dog food industry, though regulated, is far from strict about the quality of the ingredients that go into dog food. There are huge variations in the quality of ingredients used by even very reputable companies. As a dog owner, you will do well to read labels and compare ingredients to be sure you are getting the best quality for your money.
Manufacturers are required to list the ingredients by weight, with the heaviest appearing first. This does not necessarily indicate how much of that ingredient is present. For instance, some sort of meat may be listed as the first ingredient, followed by several meat by-products and grains. Because the meat contains a lot of water, it is heaviest and therefore listed first. However, the food probably contains far more grain and by-products than the higher-quality and more nutritious meat.
A processed dog food can't be more than half meat, since any greater percentage would jam up the mechanism that processes the food and cause production problems. Production problems mean huge losses of revenue and are avoided at all costs.
Here is a list of what to look for in a quality dog food:
A whole meat source as the first two ingredients, such as chicken and chicken meal. Avoid a food that lists a grain as two of the top three ingredients.
The meat content should be higher than the grain content.
Whole unprocessed grains, vegetables, and other food should appear farther down the list.
Preserved with mixed tocopherols (vitamin E, vitamin C).
Meat and meat meal should be labeled as coming from a specific source. Look for “chicken” rather than “poultry” and “chicken meal” rather than “poultry meal.”
Even when you have this list to guide you in choosing a high-quality food, you may still run into problems deciphering labels. For instance, a food might list a meat ingredient first but then follow that with two grain sources. Meat by weight is heavier, but if there are no other meat proteins listed in the first three ingredients, it is likely that the food contains proportionally more grain than meat.
Quality of Meat Sources
The quality of the meat source is the most important part of a food. The quality of the protein source separates the really good food from the really poor quality ones. The protein source in dog food should be from meat versus a plant source. The dog's body is not designed to process huge amounts of grains, and the canine anatomy is designed to thrive on high-quality protein from a high-quality meat source.
Meat sources also come as meat meal, which is an acceptable form of protein and still of good quality. Meal is a rendered product. It is cooked, dried, ground, or otherwise processed but still a good source of protein. Meal cannot contain blood, hair, hoof, horn, hide, manure, or stomach contents. Meat meal and bone meal have the same prohibitions except they can include bone.
In general, stating the source of the protein is better than a general label. This means that chicken meal is better than poultry meal, chicken by-products better than poultry by-products, and chicken digest better than animal digest.
Meat by-products are lower-quality meat sources. A by-product departs greatly from a nutritious source of protein. By-products can include some meaty muscle, but also beaks, feet, entrails, kidney, brain, liver, bone, lungs, hair, hooves, manure, and other waste products. By-product is the trash of the protein world: mixed up, ground together, and sold as a source of protein (sometimes the sole source of protein) in a dog food.
A product called meat digest is the worst of all in quality: this is by-product treated with heat and water to form a slurry, further diluting the already low-quality source of protein.
A good general rule of thumb to follow is that anything less than meal is not fit for a high-quality diet in dog food. Avoid dog foods with less than desirable sources of protein.
The Trouble with Corn
Corn is a source of protein, but a food that uses it as its major source of protein is not a high-quality food. Corn and corn products usually make up most of a cheap food's protein content, supplying a substandard source of nutrition to any dog fed this diet.
Dog-food manufacturers often use a combination of a high-quality source of protein (like chicken or beef) mixed with a very low-quality source like corn. If corn is listed among the top three ingredients on the label, the majority of the protein likely comes from the corn source, meaning the food is not high in quality.
Corn is a cheap source of protein, and dog food manufacturers like to use it because it costs less and does not gum up their food-processing machines. This is true of corn gluten meal as well, an even cheaper source of corn protein found in many bargain dog foods to replace a higher quality source of meat protein. Not only is corn a poor protein source, but some dogs are actually allergic to corn and corn by-products.