The last thing your pet should be eating is plastic

A new study found microplastics in over 75% of commercial pet foods — including the brands you probably trust most. Here's what that means for your dog or cat, and what you can actually do about it. You open a tin of wet food or scoop out the kibble and feel like you're doing right by your pet. You've picked a brand you trust. You've read the label. Job done, right?

Well, a new study from the Universities of Sussex and Exeter has found something that's hard to shake once you know it: microplastics are turning up in more than three-quarters of commercial pet foods, and not just the cheap ones. Brands like Royal Canin, Pedigree, Iams, Whiskas, Lily's Kitchen, and Scrumbles all showed up in the findings. The study, published in the peer-reviewed journal Environmental Toxicology and Chemistry in June 2026, tested 38 products across every price range and food format.

Seventy-six percent of those products contained microplastics. Eighty-four percent of the brands tested had at least one affected product.

So, is the pricier food any safer?

Honestly? A little but not as much as you'd hope. Value-range foods did show the most contamination. But premium products weren't off the hook either. Dry food has more microplastic particles per gram, but wet food isn't necessarily the safe option either — because pets eat larger portions of it to feel full, meaning the total amount they swallow can actually be higher.

The numbers at the high end of contamination are genuinely startling. A large dog eating one of the most affected foods could be taking in more than 2,300 microplastic particles every single day. Over a year, that's close to a million particles.

But does it actually hurt them?

This is where science gets uncomfortable. Research shows that microplastics don't just pass through; they interact with tissue and accumulate over time. In animals, exposure has been linked to gut inflammation, liver damage, disrupted immune responses, and even changes to gut bacteria.

Studies have found microplastics in the internal organs of deceased dogs and cats — in the kidneys, liver, lungs, and intestines. Dogs appear more vulnerable to wider systemic effects, while cats seem particularly prone to chronic gut inflammation from fibrous plastic particles.

Researchers are also starting to describe pets as environmental sentinels, meaning what shows up in their bodies often reflects what's in ours. They eat similar food, breathe the same indoor air, and drink from the same sources. If something is quietly affecting them, there's a good chance it's quietly affecting us too.

How is plastic getting into the food?

The supply chain of commercial pet food is more plastic-dependent than most of us realise. Ingredients arrive in plastic-lined sacks. Factories use plastic conveyor belts and equipment. Some meat sources still have plastic livestock ear tags attached when they're processed. Leftover human food, sometimes still in its original plastic wrapping, makes its way into production lines.

It's not one factory making a mistake. It's a food system built on plastic at almost every stage.

What can you actually do to protect your pet?

Here's the honest truth: you can't completely eliminate exposure. There are no confirmed microplastic-free pet foods on the market yet. But you can reduce it, and that matters.

Small switches that make a difference:

•       Swap plastic bowls for stainless steel or ceramic ones. Scratched plastic bowls shed even more particles into food and water.

•       Store dry kibble in its original bag — sealed — rather than decanting it directly into a plastic bin.

•       For wet food leftovers, store in glass or stainless steel rather than plastic containers.

•       Look for foods packaged in tetra packs, glass jars, or foil pouches where possible, as these may reduce post-production plastic leaching.

•       If budget allows, mid-range products performed better in the study than value-range options.

•       Rotating between wet and dry food formats may help avoid heavy reliance on a single source.

Some research also points to nutrients that support the body's natural detox and repair systems such as things like sulforaphane (from broccoli sprouts), milk thistle, and glutathione have been studied for their roles in liver function, gut integrity, and antioxidant defence. If you're concerned, it's worth speaking to your vet about whether any of these are appropriate for your pet.

The bigger picture

This isn't a reason to panic or throw out your pet's food. The study doesn't name a safer alternative, and there isn't one we can point out to you yet. What it does ask for is more awareness —from pet parents, from brands, and from regulators.

Until labelling becomes more transparent and supply chains are held to a higher standard, the best any of us can do is stay informed, make the small changes we can, and pay attention to what goes into that bowl. Because it turns out, it matters quite a lot more than any of us knew.

(Source: Universities of Sussex and Exeter, Environmental Toxicology and Chemistry, June 2026.)