The Best Costco Dog Food, According to Experts

Making Sense of Dog Food Labels

Picking the right dog food can be a bewildering experience. Chicken, salmon, turkey, or beef? Brown rice or grain-free? Kirkland, Purina, or Blue Buffalo? We talked to veterinary nutrition experts, reached out to brands, and conducted our own research to answer those questions. To make your life easier, we also applied that knowledge to Costco’s selection of dog food to determine the highest-quality, bang-for-your-buck chow.

What Makes a Good Dog Food?

• Look for an AAFCO statement.

Although the organization doesn’t directly test or regulate pet food, the nonprofit Association of American Feed Control Officials (AAFCO) establishes guidelines for animal feed. Beyond checking that a diet is AAFCO compliant (look underneath the nutrition facts), you should also ensure that the label mentions “feeding tests” or “feeding trials,” as this means the company has tested its food, according to the Nutrition Support Service at the University of California—Davis’ veterinary hospital.

• Buy “complete and balanced” dog food.

If the nutrition adequacy statement says that a food is “complete,” that means it includes the required nutrients for an adequate diet. Avoid labels that use adjectives like “short-term,” “intermittent,” or “complementary” if you’re looking for an everyday chow.

• Avoid dog food that’s made in China.

Because China has fewer regulationsthan the United States, pet owners should buy domestically produced dog food, according to Dr. Richard Hill, associate professor at the University of Florida’s College of Veterinary Medicine. 

• Choose large, well-established brands that hire nutritionists and publish research.

Check a company’s website to see if they’ve hired board-certified veterinary nutritionists or Ph.D.-educated animal nutritionists. For example,Purina has a list of its top nutritionists on its website, as well as a dedicated research branch.

• Ignore internet pet food rankings and be critical of marketing.

A representative from UC Davis’ Nutrition Support Service said to ignore online pet food rankings, which are “often misinformed and largely based on emotion rather than scientific principles.”

• Skip “BEG” (boutique, exotic-ingredient, or grain-free) diets.

BEG diets often come from small companies that lack the proper facilities and research capabilities, and they can include strange, untested meats like kangaroo. Steer clear of these, as they can lead to serious problems like heart disease.

Best: Blue Buffalo Adult Dog Life Protection Formula — Chicken and Brown Rice

Photo credit: Costco

Price: $43 ($1.13 per pound)

AAFCO statement: Yes

Grain-free: No

Country of origin: Made in the U.S. with global ingredients

As a well-established company that produces American-made, AAFCO-compliant dog food, Blue Buffalo ticks nearly all the boxes without being too expensive. When we contacted Blue to ask whether they had experts on staff, they were also quick to reply that they had a “growing team of veterinarians, Ph.D. animal nutritionists, and food scientists.”

Runner-Up: Kirkland Signature Formulas

Photo credit: Costco

Price: $29 (73 cents per pound) and up

AAFCO statement: Yes

Grain-free: No

Country of origin: Made in the U.S. with global ingredients

All of Costco’s affordable in-house dog foods are produced by the Diamond Pet Company, which claims “experts and scientists” have formulated its diets. The statement, which you can find on the website, is a bit vague, and Diamond didn’t respond when we asked for more information. Nonetheless, Kirkland’s Signature Formulas all have AAFCO statements and are made in the U.S. Just stay away from grain-free diets at Costco, meaning most of the Kirkland Signature Nature’s Domain line.

The Bottom Line

Shop for AAFCO-compliant, American-made dog food from brands that hire experts and invest in their own research. At the same time, don’t blindly fall for trends and buzzwords like “grain-free” and “natural.”

Frequently Asked Questions

Does it matter where dog food is made?

Yes. For example, dog food regulations are stricter in the U.S. than in China, so try to buy American-made kibble.

Does the type of meat matter?

Unless your pet has an allergy or sensitivity to certain foods, it doesn’t matter what type of meat you feed them, according to Dr. Hill.

Where can I find out about dog food recalls?

You can find the most recent recalls on the Food and Drug Administration website.

Is expensive dog food better?

Not necessarily. As a UC Davis nutrition expert noted above, pet food rankings and marketing buzzwords aren’t usually based on science. Instead of judging a dog food by its package or price, look for a reputable brand with an AAFCO statement.

Does it matter if food is organic or natural?

There’s “no objective scientific evidence” that natural or organic diets lead to better outcomes for pets, according to Ohio State University’s Veterinary Medical Center. But it’s worth understanding what these words mean.

• Natural: According to the AAFCO, natural foods are not mandated to be safer, and many natural products can contain traces of “chemically synthetic compounds.” That said, pet food labelers in select states do have to comply with the AAFCO’s definition of natural — “a feed or feed ingredient derived solely from plant, animal or mined sources” — so there are some regulations in place.

• Organic: On the other hand, the National Organic Program (NOP) regulates organic foods, which rules out “synthetic fertilizers, sewage sludge, irradiation, and genetic engineering.” While specific criteria are being developed for pet foods, right now all animal diets have to comply with the standards the NOP sets for human food.

Should dog food be grain free?
The short answer is no. “No study has ever shown grain-free to be superior to grain-inclusive diets,” according to the American Kennel Club. In fact, grain-free kibble could be linked to a form of heart disease. The FDA investigated this connection in 2018, though its findings have been inconclusive.

Where can I find more information?

The World Small Animal Veterinary Association (WSAVA) has published a comprehensive guide on selecting pet foods. UC Davis’ Nutrition Support Service also recommended the SkeptVet blog and the clinical nutrition website from Cummings School of Veterinary Medicine at Tufts University. In general, look for evidence-based, research-backed information when you research.