Just like processed human food, dog food is made with ingredients from dozens of sources, says Downey, who also has a background in veterinary nutrition from the University of Pennsylvania School of Veterinary Medicine. And quality varies greatly. Between two products with identical ingredients lists, one could contain poor-quality cuts of meat with a higher potential for contamination, while the other product could contain high-quality ingredients that have been rigorously tested. Yet government regulations restrict what pet-food manufacturers can print on their packages, making it nearly impossible for you to determine which one is the higher-quality pet food.
But that doesn't mean you still can’t find healthy pet food. Downey recommends that you look for three specific things whenever you’re shopping for a new dog food:
“Avoid anything that says ‘by-products,’ ” he says. They're usually waste products, like necks, feet, intestines, and feathers (in the case of chicken) that can carry a potential for contamination. For instance, some organ meats not immediately refrigerated after an animal was slaughtered for humans are considered unfit for human food but okay for use in dog food. Look for foods that list specific meats, as well, such as "chicken" or "chicken meal" rather than "poultry" or "poultry meal." Generic labels usually indicate meat from a variety of sources.
Every dog-food bag is required to list a nutrient analysis that breaks down the food’s protein, fat, fiber, and moisture content. It doesn’t give you many clues as to salmonella contamination, but it can give you some sense of product quality.
Here’s what Downey recommends looking for under each term:
Protein—Aim for a protein content of 23 percent for older adult dogs, 26 percent for active dogs, and 30 percent if you’re buying a grain-free dog food. Don’t be tricked into thinking protein contents higher than 32 percent are better for your dog. Dogs can’t physically utilize protein in contents higher than that, he says.
Fat—Pet obesity is a huge problem, pun intended. “Close to 60 percent of dogs in this country are overweight,” Downey says. So a low-fat dog food is key. A normal-weight dog of any age should eat a food with 10 to 15 percent fat, and one trying to lose weight should eat food with 8 to 10 percent fat. “More important, though, is the ratio of fat to protein,” Downey says. If you’re eating a food on the low end of the protein range, it should also be on the low end of the fat range.
Fiber—“I’ve always believed in low-fiber diets,” he says. They’re healthier for dogs. So aim for a food with 3 to 4 percent fiber.
Moisture—Although this is required on dog-food labels, most dry dog foods have the same moisture content, about 10 percent, says Downey.
3. Where It's From
Is it a small family-owned company or a big conglomerate? “A lot of the good, smaller dog-food companies have been bought out by the big boys,” Downey says. "But are they maintaining the quality?" He says a number of small regional brands of dog food exist that are superior to the major national brands. Though it’s not always a guarantee, smaller companies tend to have a better handle on quality control.