How do I read the dog food ingredient list?
Like packaged food for people, pet food must list ingredients by weight, starting with the heaviest. But if the first ingredient is a type of meat, keep in mind that meat is about 75% water, according to the FDA.
Without that water weight, the meat probably would fall lower on the ingredient list. Meat meals, such as chicken meal or meat and bone meal, are different; most of the water and fat have been removed, which concentrates the animal protein.
What are byproducts, and should I avoid dog foods that contain them?
Veterinarians say that’s a matter of personal choice. Any pet food labeled as “complete and balanced” should meet your dog’s nutritional needs.
Liver, which is a byproduct, is rich in nutrients such as vitamin A. Meat byproducts also can contain blood, bone, brains, stomachs, udders, and cleaned intestines, according to the Association of American Feed Control Officials. Byproducts don't include hair, horns, teeth, and hooves, although an exception is allowed for amounts that occur unavoidably during processing.
Meat meal also may contain animal parts that many people consider to be byproducts. An ingredient listed as “chicken” or “beef” may include the heart, esophagus, tongue, and diaphragm. Although all these ingredients may sound unpalatable to you, your dog would probably disagree. So don’t necessarily balk if you see byproducts in the ingredients list.
Federal rules to guard against the spread of bovine spongiform encephalopathy (mad cow disease) ban some previously allowed cattle and buffalo parts in animal feed, including pet food. The FDA rule bans the inclusion of body parts from any animal that has tested positive for mad cow disease, as well as brains and spinal cords from older animals, as these are considered to be at higher risk of the disease.
What are all those chemical-sounding names lower on the ingredient list?
Preservatives, artificial colors, and stabilizers in pet food must be either approved by the FDA or be generally recognized as safe, a category that includes everything from high fructose corn syrup to benzoyl peroxide, used to bleach flours and cheese. Manufacturers must list the preservatives they add, but they do not always list preservatives in ingredients such as fish meal or chicken that are processed elsewhere.
Some pet owners don't want to buy food that contains the synthetic preservatives BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), or ethoxyquin. These preservatives stop fats from turning rancid and can keep dry dog food fresh for about a year, but their safety has been questioned by some consumers and scientists. But the FDA says they’re safe at the level used in dog food.
“There is a debate about whether there is a need to avoid artificial ingredients like these, as conventional safety testing says they’re fine,” says Susan Wynn, DVM, AHG, a nutritionist for Georgia Veterinary Specialists in the Atlanta area and a clinical resident in small animal nutrition with the University of Tennessee College of Veterinary Medicine. “I wouldn’t want them in my diet every day though, and I try to avoid them in my dog’s daily diet.”
Ethoxyquin came under scrutiny in the 1990s after complaints of skin allergies, reproductive problems, cancer, and organ failure in some dogs given food with this preservative. In 1997, the FDA asked dog food makers to halve the maximum allowed amount of ethoxyquin after tests conducted by manufacturer Monsanto Company showed possible liver damage in dogs fed high levels of the preservative.
Some manufacturers no longer use ethoxyquin, BHA, or BHT, instead using natural preservatives such as vitamin E (mixed tocopherols), vitamin C (ascorbic acid), and extracts of various plants, such as rosemary. Those also keep food fresh, but for a shorter period. Be sure to check a food’s “best by” date on the label before buying or feeding it to your pet.
“If you want shelf life, it’s better to have chemical preservatives,” says Joseph Wakshlag, DVM, PhD, assistant professor of clinical nutrition at Cornell University College of Veterinary Medicine. “They’re added at amounts that won’t harm the dog, and it creates a more stable fat. Rancid fat can cause liver enzymes to go up, and diarrhea.”