As a longtime dog owner, I assumed that each bag of my dogs’ commercial pet food was closely monitored by the federal Food and Drug Administration (FDA). It turns out I was wrong.

More than 102 million U.S. households own a dog or a cat, and thousands more have fish, birds, or reptiles. The resulting pet food industry is massive — Americans spent $65 billion on pet food and treats in 2023 alone.

But regulation of pet food in the U.S. is spotty. While it’s true that the FDA regulates the ingredients found in commercial pet food, the agency doesn’t approve individual products or brands. What’s more, FDA oversight of the sprawling industry is shrinking thanks to mass federal layoffs, including at its Center for Veterinary Medicine, which regulates pet food.

Only the FDA and states have regulatory authority over commercial pet food in the U.S. The agency has regulated commercial pet food since 1938 and requires that it be safe for animals to consume, produced under sanitary conditions, free of harmful substances, and labeled truthfully. Each state also undertakes its own label review for each product and requires products be registered.

The FDA inspects pet food manufacturing facilities and initiates recalls. There were 17 pet food recalls in 2024, mostly due to salmonella and/or listeria contamination. And while the FDA does not approve brands or products, it does approve individual ingredients used in those products.

The basic idea is this: If a bag of dog food is labelled truthfully, free of harmful substances, produced in a sanitary way, and contains specific ingredients approved by the FDA, that bag can be sold in the U.S. But a product need not be especially nutritious to meet these requirements and go to sale. The FDA has no role in ensuring products that go to market are nutritionally sufficient or of high quality.

Instead, two nongovernment organizations have stepped in to set the standard:  the Association of American Feed Control Officials (AAFCO) and the World Small Animal Veterinary Association (WSAVA).  

Though neither AAFCO nor WSAVA have regulatory authority, they both produce guidelines that pet food manufacturers try to meet, and consumers can use to distinguish an ostensibly “good” food from a “bad” food.

AAFCO is comprised of state and federal feed officials — experts in livestock and pet feed who set standards to define pet foods as “complete and balanced.” To earn this designation, products must simply meet one of AAFCO’s dog or cat food nutrient profiles, and/or pass a feeding trial.

WSAVA guidelines go much further, requiring that brands employ a board-certified nutritionist or scientist to formulate the food. Additionally, brands should oversee quality control and own the manufacturing facilities where food is made. WSAVA requires that feeding trials go above and beyond those of AAFCO.

Unlike AAFCO, WSAVA’s members include major pet food conglomerates, including Nestle, Mars Petcare, and Colgate-Palmolive. Representatives from Nestle’s Purina sit on WSAVA’s nutrition committee and also make an annual $100,000+ donation to WSAVA. Some smaller brands have decried corporate involvement in setting these guidelines, arguing that it unfairly tips the scales.

All of this is opaque to consumers.

With numerous voices of authority on pet food and confusion about whom to trust, pet owners often turn to a source where misinformation thrives: the internet.

There, fad diets take hold. Two recent examples are grain-free and raw diets.

Grain-free diets exploded in popularity in the 2010s, as armchair experts seized on scant research about their anti-allergy benefits. Sales of grain-free food soared to nearly $5.5 billion in 2019.

But from 2018 to 2022, the FDA began investigating nearly 1,400 complaints of dilated cardiomyopathy (DCM) in dogs (and a small number of cats). Canine DCM reduces the heart’s ability to pump blood throughout the body and can result in severe illness and sudden death. Most affected pets had been eating grain-free diets.

Although the FDA’s investigation fizzled out without a definitive conclusion, numerous studies have since suggested that high levels of pulses (as in the seeds of a legume plant) may be to blame instead.

Raw diets have also taken hold, spurred by online proponents of a “natural” diet. Raw diets consist of raw meat, eggs, and bones, as well as uncooked vegetables or fruits. These diets carry the risk of foodborne illness, including bird flu, seen as recently as January 2025 in California. Officials confirmed that indoor cats were exposed to the live virus in raw food and milk.

The rigorous inspection and monitoring services performed by FDA veterinary regulators were critical to exposing the dangers of these two fad diets. With significant cuts to their workforce, we could expect this on-the-ground oversight to suffer.

We have some local support, though.

Americans place great trust in their local veterinarians who serve as the first line of expertise and monitor patterns like fad diets. But vets face two challenges in delivering nutrition guidance to clients: a workforce shortage and training gaps.

Nearly all U.S. states have a veterinary shortage. There are not enough vets to meet the 60% increase in household pet ownership since 1991.

Many practicing vets also don’t feel adequately trained to dispense nutrition advice to their clients. Researchers from the University of Wisconsin found that 57% of surveyed vets received little or no formal training in small animal (e.g. dog and cat) nutrition.

One way to fix this is changing continuing education (CE) requirements for vets. While CE requirements vary, states could require vets to earn a certain number of nutrition CE credits to obtain or renew their license. This would close gaps of knowledge, better equip vets to make recommendations to their clients, and reduce the circulation of nutrition misinformation.

I feel a big responsibility to feed my dog safe, high-quality, nutritious food. With the recent layoffs of veterinary experts at the FDA, I feel even less confident that I can trust what I find at the pet store.

Katherine O’Malley, M.P.H., is a senior policy analyst at Boston University School of Public Health.