A 2026 peer‑reviewed study found microplastics in 76% of commercial pet foods it tested. That figure appeared in headlines and understandably worried dog and cat owners. However, the number needs a denominator correction to be interpreted accurately. The study examined 38 products, each tested with six separate one‑gram samples. In 29 of those 38 products (76.3%) at least one of the six replicates contained microplastic fragments. But when you look at the 228 individual one‑gram samples, only 63 were positive—27.6%. Both figures are correct; they simply answer different questions.
This article explains what the study actually found, what the wet‑versus‑dry comparison means for daily feeding, the possible sources of contamination, and the sensible steps owners can take without overreacting.
What 76% means—and what it doesn’t
| Metric | Finding |
|---|---|
| Products with microplastics (≥1 of 6 replicates positive) | 76.3% (29 of 38 products) |
| Total one‑gram samples with microplastics | 27.6% (63 of 228 samples) |
The product‑level prevalence (76.3%) shows how widely positives were distributed across the tested products: most products had at least one positive result among six replicates. The sample‑level prevalence (27.6%) describes the tested one‑gram units themselves. It should not be converted into the odds for any future scoop, brand, or country because the study was not a random survey of the whole market.
How the study was designed
Researchers bought 38 products available in the United Kingdom: 14 cat foods, 16 dog foods, and eight hedgehog foods. Six retail units from different batches were sampled for each product, producing 228 one‑gram replicates. The material was digested with a 10% potassium hydroxide solution, filtered through 1.2 μm glass filters, examined under a dissecting microscope, and identified by Fourier transform infrared spectroscopy. The method therefore did not measure nanoplastics or particles below its practical detection range.
Wet food versus dry food: an unexpected exposure twist
When expressed as particles per gram across all samples, dry food had a higher average—0.4 pieces per gram—compared with 0.3 pieces per gram for wet food. At first glance, dry diets appear more contaminated. However, the paper points out that estimated daily exposure could be higher for wet food. The reason is simple: because moisture‑rich canned foods contain fewer calories per gram, dogs and cats need to eat a larger mass of wet food to meet their daily energy requirements. A bigger bowl translates into more grams consumed, and thus a higher total number of microplastic particles ingested each day, even though the concentration per gram is slightly lower.
That does not make either format “safer.” Dry food had more particles per gram in this dataset, while the paper’s intake scenarios estimated higher exposure from larger wet-food portions. Those are different comparisons, and neither is a health-risk measurement. Owners should not switch formats solely on the basis of this study.
Where the microplastics might come from
The researchers did not trace the particles back to a single source, and they did not claim that packaging was the proven culprit. Instead, they listed several plausible pathways, each carrying a different degree of confidence:
- Ingredients: Fish meal, meat‑and‑bone meal, and plant‑derived powders can contain microplastics that were already present in the raw materials before they arrived at the pet‑food factory.
- Processing: Grinding, extrusion, and other manufacturing steps can shed plastic fragments from machinery or conveyors.
- Textiles and airborne fibers: Synthetic fibers from clothing, filters, or factory environments may settle onto ingredients or finished products.
- Industrial materials: Bits of plastic from containers, hoses, or seals used in production can enter the food stream.
- Packaging: Contact with plastic bags, pouches, or can linings is a possibility, but the study did not identify specific packaging‑shedding particles.
Because multiple routes are possible, switching to a brand that uses different packaging does not guarantee a lower microplastic load.
What the study cannot tell owners
The paper is an exposure survey, not a health‑risk assessment. The authors state clearly that animal‑health implications remain unclear. There are no accepted thresholds for safe microplastic intake in dogs or cats. Therefore, this research does not provide any basis to claim that commercial foods cause illness or to rank certain brands as riskier. It also cannot answer whether the particles pass harmlessly through the digestive tract or have any long‑term effects.
Practical steps for concerned owners
For most pets, the most important nutritional priority is maintaining a complete and balanced diet. Abrupt changes can cause digestive upset or, if a medical diet is discarded, worsen existing conditions. With that in mind, here is a proportionate action list:
- Do not abruptly replace a nutritionally appropriate diet. This exposure survey did not compare the uncertain microplastic question with the known nutritional consequences of an unsuitable or suddenly changed diet.
- Store food as directed on the label. Keep dry food in its original package inside an airtight container, in a cool, dry place. Avoid leaving food in direct sunlight or in garages where temperature swings might degrade packaging.
- Check packaging for damage. Do not buy or feed from torn, punctured, or bulging bags or dented, rusted, or swollen cans. Damaged packaging may introduce unwanted contaminants.
- Consult your veterinarian before changing a medically indicated diet. If your pet is on a prescription or therapeutic food, discuss any concerns with your vet. They can help you weigh the hypothetical microplastic exposure against the proven health benefits of the prescribed nutrition.
- Watch for replication and regulatory guidance. Single studies need to be repeated. Follow reputable sources such as the U.S. Food and Drug Administration’s animal-feed pages or the World Small Animal Veterinary Association (WSAVA) Global Nutrition Guidelines for updates.
Frequently asked questions
Is my dog or cat at immediate risk from microplastics in food?
This study did not test immediate or long‑term health effects. Its authors state that the implications for companion animals remain unclear, so the results cannot establish either safety or harm at the measured concentrations.
Are wet foods safer than dry, or the other way around?
Neither format can be called safer based on this study. The per‑gram concentration was higher in dry food, but modeled daily intake could be higher for wet food because pets eat a larger mass. The study did not compare health outcomes between feeding formats.
Should I switch to homemade or raw food to avoid microplastics?
No, not on this evidence alone. Homemade and raw diets carry well‑documented risks of nutritional imbalance and bacterial contamination. Microplastics are ubiquitous in the environment, so avoiding commercial pet food does not guarantee a plastic‑free diet. Any diet change should be guided by a veterinarian or a board‑certified veterinary nutritionist.
What can I do right now while we wait for more research?
Follow the practical steps listed above: store food correctly, avoid damaged packaging, maintain your pet’s current balanced diet, and talk to your vet if you have specific health concerns. Stay curious but avoid alarmist conclusions from a single study.
Sources
- Primary peer‑reviewed study: Microplastics in commercial pet foods, Environmental Toxicology and Chemistry (2026) – the original paper, including all sample‑level and product‑level data.
- Industry summary: Petfood Processing article (2026) – a trade‑press report that describes the study’s main findings.
- Separate 2026 Spanish study (corroborating context): Exploratory analysis of microplastics in five dry‑food brands – a smaller, independent study limited to dry dog and cat foods; useful as supplementary context.
- FDA pet‑food regulation and owner safety: U.S. Food and Drug Administration – Pet Food – official information on how pet food is regulated and how owners can report concerns.
- WSAVA Global Nutrition Guidelines: World Small Animal Veterinary Association – evidence‑based guidance on selecting and discussing pet foods with your veterinary team.
This article provides research interpretation, not veterinary diagnosis or treatment advice. Always consult your veterinarian before changing a medically indicated diet.