Published August 12, 2025 • Updated December 22, 2025
Reviewed by Julie Miller, BA in Language Arts, Editorial Lead, Dr. Killigan’s
TL;DR: Pet food labels can hide a lot in vague terms. This guide shows what to look for, what to research and which questions to ask before you buy.
Pet food label questions, answered
Toxins in pet food: what does that usually mean?
Most people use “toxins” as a catch-all for unwanted exposures—like contaminants, residues or chemicals that may come from ingredients, processing or packaging. What matters most is transparency: clear sourcing, testing and straightforward labeling.
Dog food with PFAS: is it in the food or the bag?
Many concerns focus on packaging—especially grease-resistant materials—because some chemicals can migrate from packaging into food over time. If you’re worried, ask the brand what their packaging is made of and whether they test for packaging-related chemicals.
Pet food ingredients to avoid: what should I look for?
Rather than a one-size-fits-all “avoid” list, watch for terms that are vague, hard to verify or used to hide sourcing. When in doubt, ask the manufacturer for specifics—or talk with your veterinarian about what’s right for your pet.
Forever chemicals in pet food bags: what can I do?
Ask what materials are used in the bag or lining and whether the brand tests for packaging-related chemicals. If they can’t answer clearly, consider choosing a brand that publishes sourcing and testing information.
Before we go further, here’s what sparked this deep dive.
Why we started looking into “hidden ingredients”
I walked into what looked like a neighborhood bar—gold lettering peeling from the glass door. Inside, it wasn’t the usual crowd. One person nursed a whiskey; another wore a bright smock and held hair shears. It took a second to click: part bar, part barber shop—scotch and scissors.
While I waited, the barber mentioned he also worked as a dog groomer nearby. Then he said something that stuck with me: he was worried about “forever chemicals” showing up not just in pet food, but in the packaging it comes in. That conversation sent me down a rabbit hole—because if labels can be unclear, it’s hard for pet owners to know what’s worth questioning and what’s just marketing.
That’s what this guide is for: a practical way to read the label, spot vague terms and ask better questions before you buy.
Bioaccumulation explained (in plain English)
Bioaccumulation is the gradual buildup of certain chemicals in a living body over time—often over months or years. Instead of causing an obvious, immediate reaction, some exposures can add up slowly—especially when they come from everyday sources like food, water, household dust or packaging.
For pets, repeated exposure is the common thread. The practical takeaway is simple: prioritize brands (and packaging) that can clearly explain what they use—and what they test for.
Environmental Working Group (EWG) has reported that dogs and cats tested in a small study carried a mix of industrial chemicals in their blood and urine—some at levels higher than those typically reported in humans.
American pets are polluted with even higher levels of toxic industrial chemicals than humans.
The takeaway isn’t panic. It’s a reminder that transparency makes it easier to choose with confidence.
Cats and chemicals: why small exposures can matter
Cats can be more sensitive to certain chemicals than dogs or humans because their bodies have a reduced capacity to metabolize some compounds.
Worth knowing: Because cats groom themselves so often, they’re more likely to ingest whatever ends up on their fur—like household dust or residues from surfaces and packaging.
Next, we’ll walk through the label terms that deserve a closer look and the packaging questions worth asking.
What to look for on a pet food label
Pet food labels can be useful—but they can also be vague. Here are five practical things to look for when you’re comparing brands and doing your research.
1. Vague “catch-all” ingredients
What it can look like: “natural flavors,” “animal digest,” “meat meal” (without a specific animal), “by-products” (without clear sourcing).
What to do: If a term is broad, ask the brand to define it in plain language and tell you the source. If they won’t, choose a brand that will.
2. Feel-good claims that don’t tell you anything measurable
What it can look like: “premium,” “clean,” “holistic,” “natural,” “vet recommended,” “no fillers,” “made with quality ingredients.”
What to do: Don’t just accept the claim—ask for the standard behind it: sourcing, testing and documentation.
3. Ingredient lists that make comparison hard
What it can look like: similar-sounding formulas with very different protein sources, fats or additives; unclear wording that makes it hard to tell what’s doing the nutritional heavy lifting.
What to do: Compare the first 5 ingredients across brands (that’s often where the core formula shows up). If you’re unsure what a term means, ask the manufacturer—or check with your veterinarian for your pet’s needs.
4. Transparency signals you can verify (not just slogans)
What it can look like: An ingredient glossary, clear sourcing statements, accessible customer support, published quality/testing standards and straightforward explanations of “why this is in here.”
What to do: If a brand is transparent, they’ll make it easy to find—and easy to confirm.
5. Packaging questions (when you’re researching PFAS/“forever chemicals”)
What it can look like: Packaging details that aren’t disclosed on the ingredient label—especially vague answers about bag linings or grease-resistant materials.
What to do: Ask what the bag/lining is made of, whether it’s grease-resistant and whether they test packaging materials (or finished product) for packaging-related chemicals. If answers stay vague, consider a more transparent brand.
Why transparency matters (and why recalls happen)
In March 2007, a wide range of pet foods were recalled after reports of pets developing kidney problems. Investigations linked the issue to contaminated ingredients (including melamine and cyanuric acid) used in certain “cuts and gravy” style foods.
The point isn’t to relive worst-case headlines—it’s to highlight what that moment taught pet owners: when a supply chain is complex, clear labeling, testing and fast communication matter. Today’s pet food market is bigger and more diverse than ever, which makes transparency even more important—especially when you’re trying to verify claims and understand sourcing.
What to do now (simple, practical):
- Check reputable recall sources periodically (and keep your pet’s food brand + lot info handy).
- Favor brands that explain ingredients clearly and can tell you what they test for (and how often).
- If you're uncertain about what's best for your pet, use your veterinarian as a backstop for diet decisions.
What research has found (and how to use it)
Environmental Working Group (EWG) published its Polluted Pets investigation, which used pooled blood and urine samples from 20 dogs and 37 cats and reported that pets were contaminated with 48 of 70 industrial chemicals they tested.
EWG’s breakdown is detailed: in their reporting, dog samples contained 35 chemicals (including 11 they categorized as carcinogens and 24 as neurotoxins) and cat samples contained 46 chemicals (including 9 they categorized as carcinogens and 34 as neurotoxins).
EWG also notes an important caveat: for nearly all chemicals included, health risks in pets haven’t been studied—which is why this is best used as a transparency signal, not a panic button.
How to use this information:
- Don't panic—use it to guide better questions.
- Choose the most transparent brand you can verify (ingredients, sourcing, testing).
- Treat vague answers as an answer.
PFAS: what they are and why packaging questions come up
PFAS (per- and polyfluoroalkyl substances) are a large group of man-made chemicals used in some materials to resist grease, water and stains. You’ll see them discussed in many everyday products—and sometimes in the context of grease-resistant food packaging.
That’s why PFAS conversations often start with the bag, not the ingredient list. Packaging materials and linings aren’t always disclosed on-label, so if PFAS is part of your research, start with Packaging questions (point 5) above.
How Dr. Killigan’s helps (when you’re researching products used around your home)
If you’re the kind of pet owner who reads a label and asks follow-up questions, that instinct will serve you well beyond the food bowl. The same approach applies to the products you use in kitchens, living spaces, entryways and anywhere pets (and kids) spend time: look for clear directions, straightforward ingredients and brands that can explain what’s in the product—and why.
At Dr. Killigan’s, we take that “show your work” standard seriously. We build plant-powered pest control for real homes and we try to make the details easy to understand—so you can make choices with Confidence, Peace and Control.
EWG has argued that companies should be expected to “prove chemicals are safe before they are sold.” We agree with the principle: transparency shouldn’t be a treasure hunt—especially for products you use repeatedly around the people (and pets) you love.
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