Microplastics in Pet Food

A study published in June 2026 found microplastics in most of the pet food products it tested. The research came from the University of Sussex and the University of Exeter, was supported by the British Hedgehog Preservation Society, and appeared in the journal Environmental Toxicology and Chemistry.

The figure doing the rounds is “over 75%”. That number is real, but the detail behind it tells a more useful story than the headline.

What the study measured

Researchers analysed 38 dog, cat and hedgehog food products sold in the UK: 22 dry and 16 wet, across 19 brands. Microplastics turned up in 84% of brands, 76% of products, and 27% of individual samples. Cheaper “value range” products tended to contain more than the more expensive ones, though the pricier products were not free of it either.

The lead researcher, Emily Thrift, noted that microplastics were found in 16 of the 19 brands tested, including very well-known names. The paper did not publish a list naming specific brands or products.

The part the headlines skip

Dry food actually had a higher concentration of microplastics per gram than wet food. The reason wet food gets singled out is portion size. Because wet food is mostly moisture and lower in energy per gram, an animal has to eat much more of it to meet its daily needs. This is the same energy-density gap behind the wet versus dry question generally. More food eaten means more particles ingested, even at a lower concentration.

To put a number on it, the researchers estimated a large dog (35 kg) on a wet diet could ingest around 313 microplastic particles a day, with a modelled range of roughly 162 to 2,314 depending on the food and the assumptions used.

What this means for cats

The published daily figure is for a large dog, so the headline number does not transfer directly to a cat. A cat eats far less by weight, which drags the absolute count down. The underlying point still applies, though, and arguably applies more: many cats are fed predominantly wet food, which makes the wet versus dry intake dynamic central to how a typical cat is actually fed.

Where the plastic comes from is still unknown

The study did not pin down the source. The researchers flagged packaging, processing methods and ingredient quality as candidates, but were clear that telling them apart will take more work.

One pattern pointed toward ingredients: of the 21 products that contained animal derivatives, 19 returned at least one plastic-positive sample. The authors did not blame the ingredients themselves, since derivative-heavy foods also clustered in the cheaper value range that tested worse overall, and packaging or processing could produce the same result.

The way each format is manufactured, which we cover in How Cat Food Is Made, involves high heat, machinery and packaging at different stages, any of which could plausibly contribute. The measured concentrations in pet food were higher than figures reported for human food.

What the study does not tell you

It does not show that commercial pet food is unsafe. Health effects were explicitly not the focus of this research. It tested UK products and named no brands, so it cannot be mapped onto a specific product on an Australian shelf. And it offers no simple shopping rule: cheaper foods had more positive samples, but the premium group was not clean either, and the dry versus wet picture cuts both ways depending on whether you look at concentration or daily intake.

UK Pet Food, the industry trade body, responded that members' products comply with applicable food safety standards and that owners can keep feeding commercial pet food with confidence. The UK Food Standards Agency said it continues to monitor emerging data. The Blue Cross noted that pets are also exposed to plastics through bowls, toys and stored food, and that the relative size of each of those risks is not yet known.

The KibbleGuide view

This is a useful reminder of the limits of any ingredient panel. A label tells you what a manufacturer chose to add. It does not tell you what arrived uninvited through packaging or processing, and microplastics are not something current labelling discloses at all.

There is no need to panic and, on this evidence, no clean way to shop your way out of it. If you want to reduce plastic exposure more broadly, the easiest changes are outside the food itself: storing food in glass or stainless steel rather than its opened plastic packaging, and using ceramic or stainless bowls rather than plastic ones. The researchers themselves have called for manufacturers to be required to test for microplastic contamination, which is the kind of oversight Australia does not currently mandate for pet food at all.

Related reading

• How Cat Food Is Made Every cat food format, the manufacturing process behind it, and what each process does to the ingredients.
• Guaranteed Analysis Explained Why wet and dry food cannot be compared without conversion, the same energy-density gap behind the daily intake finding here.
• Is Your Cat Food Regulated in Australia? Why there is no mandatory standard, no government approval, and no central recall register here.

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