Commercial pet food sold in the United States is regulated by the FDA and must meet manufacturing safety standards similar to those applied to human food. For most pets eating conventional kibble or canned food from established brands, the food supply is generally safe. But “safe” comes with caveats worth understanding, from contamination risks to storage mistakes that can degrade food quality after you bring it home.
How Pet Food Is Regulated
Pet food manufacturers in the U.S. are required to follow the FDA’s Preventive Controls for Animal Food rule, part of the Food Safety Modernization Act (FSMA). This means every covered facility must maintain a written food safety plan that includes a hazard analysis identifying biological, chemical, and physical risks, along with preventive controls to minimize those risks. Facilities must monitor their controls, take corrective action when something goes wrong, verify that their systems are working, and maintain a recall plan.
These aren’t vague guidelines. Manufacturers must follow Current Good Manufacturing Practices (CGMPs) for production, sanitation, and process control. For canned pet food specifically, the manufacturing standards are identical to those for canned human food, designed to prevent microbial growth and toxin production.
Nutritional safety is handled separately through AAFCO, the Association of American Feed Control Officials. When a pet food label says “complete and balanced,” that phrase has a specific legal meaning: “complete” means the product contains all required nutrients, and “balanced” means those nutrients are present in the correct ratios. To make this claim, a manufacturer must either formulate the food to meet AAFCO’s nutrient profiles for dogs or cats, or run standardized feeding trials using AAFCO protocols. Look for one of these statements on the label. If a product doesn’t carry a nutritional adequacy statement, it hasn’t met those benchmarks.
What Contaminants Can Show Up
Even with regulatory oversight, contamination does occur. The two main categories of concern are biological (bacteria, mold toxins) and chemical (heavy metals).
Bacteria
Salmonella and Listeria are the most common bacterial hazards. A study published in Frontiers in Veterinary Science that tested 166 commercial pet food samples found presumptive Salmonella in 41% and presumptive Listeria in 64% of products. Dry kibble had higher detection rates than canned food: 64% of dry food samples tested positive for Salmonella compared to 26% of canned products, and 79% of dry food samples showed Listeria versus 54.5% of canned products.
These numbers sound alarming, but context matters. “Presumptive positive” means the bacteria were detected at low levels that may not always cause illness in healthy adult animals. Canned food’s lower rates reflect the sterilization process it undergoes. Still, the data confirms that dry kibble is not a sterile product, which is why handling and storage matter.
Mycotoxins
Aflatoxins, toxic compounds produced by mold that grows on corn, peanuts, and cottonseed, are one of the more serious chemical risks in pet food. The FDA’s action level for total aflatoxins in pet food is 20 parts per billion (ppb). Aflatoxin contamination has triggered several major pet food recalls over the years, with some incidents linked to pet deaths. Grain-based ingredients are the primary source, and manufacturers are required to test for and control these hazards as part of their food safety plans.
Heavy Metals
Arsenic, cadmium, lead, and mercury can enter pet food through ingredients sourced from contaminated soil or water. The FDA does not have formal regulatory limits for heavy metals in animal food but uses reference values from AAFCO and the National Research Council to evaluate safety on a case-by-case basis. The tolerance thresholds vary significantly between these two bodies. For lead in complete feed, the NRC sets a maximum tolerable level of 10 ppm while AAFCO allows up to 30 ppm. For cadmium, the gap is even wider: 10 ppm from NRC versus 0.5 ppm from AAFCO. This inconsistency means enforcement relies heavily on the FDA’s discretion rather than a single clear standard.
How Manufacturing Kills Pathogens
The extrusion process used to make kibble serves as a “kill step” for bacteria. During extrusion, the food mixture is pushed through a machine at high temperatures and pressures. Research on pathogen reduction during extrusion found that temperatures around 81°C (about 178°F) with roughly 28% moisture content achieved the greatest bacterial reduction, eliminating approximately 99.999% of test organisms. This is why conventional kibble, despite not being sterile, carries far less bacterial risk than raw food. Canned pet food goes further, using the same sealed, heat-processed sterilization method as canned food for humans.
Raw Pet Food Carries Real Risk
The CDC explicitly recommends against feeding raw pet food or treats to dogs and cats. Raw meat and other uncooked animal proteins can carry Salmonella and Listeria, and these germs have been found in multiple raw pet food products. The risk extends beyond your pet. When you handle raw pet food, bacteria can spread to kitchen surfaces, bowls, hands, and anywhere your pet licks after eating.
A common misconception is that freeze-drying, dehydrating, or freezing raw food makes it safe. These processes reduce the number of germs but do not eliminate them. If anyone in your household is at higher risk for severe foodborne illness, raw pet food poses a particular concern. This includes children under 5, adults 65 and older, pregnant women, and people with weakened immune systems.
Storage Mistakes That Reduce Safety
A bag of kibble that was perfectly safe at the factory can become problematic at home. Exposure to air, heat, and humidity causes fats in pet food to go rancid and nutrients to break down. Bacteria from the environment can also colonize food left in open containers.
Tufts University’s pet nutrition team recommends using an opened bag of dry pet food within two to three months. Diets high in fish oil tend to have shorter shelf lives. Store the food in a cool, dry place and keep it in its original bag rather than dumping it into a plastic bin, since the original packaging is designed to slow oxidation. If you do use a storage container, place the entire bag inside it. Always check the “best by” date before purchasing, and avoid buying bags so large that they’ll sit open for months before your pet finishes them.
What Makes Some Products Safer Than Others
Not all pet food carries the same level of risk. A few practical distinctions can help you choose wisely. Canned food undergoes more rigorous heat processing than dry kibble, resulting in lower rates of bacterial contamination. Products labeled “complete and balanced” with an AAFCO nutritional adequacy statement have met defined nutrient standards, while products without this statement (often marketed as treats, toppers, or supplemental food) have not. Brands that conduct feeding trials rather than relying solely on formulation provide an additional layer of validation.
Grain-free diets gained popularity in recent years, but the FDA investigated a potential link between certain grain-free formulas (particularly those heavy in legumes and potatoes) and a heart condition called dilated cardiomyopathy in dogs. That investigation has not produced a definitive causal mechanism, but it’s a reminder that “natural” or “premium” marketing terms don’t automatically mean safer or healthier. The nutritional adequacy statement on the back of the bag tells you more than the front label ever will.