Short answer: We grade the evidence behind every scientific statement from A (a controlled trial of the exact finished product, in the species it is sold for) to E (a theoretical rationale), and the strength of a claim never exceeds the strength of its evidence. Human evidence is never used for pets, and dog evidence is never used for cats. Product wording is limited to plain maintenance language, such as “supports healthy gums”, and every page is reviewed by our Science & Compliance Office before it is published.
One rule above all
The strength of a claim never exceeds the strength of its evidence. It is the second of our P.E.T.C.A.R.E. values, evidence over hype, and the rest of this standard follows from it.
In practice it means three things. We say what kind of evidence sits behind a statement. We never let evidence travel further than it can: not from people to pets, from dogs to cats, from one strain to another, or from an ingredient to a finished product. And when we do not know, we say so.
The five grades
| Grade | What it is | Example | What it can support |
|---|---|---|---|
| A | A product-specific controlled trial: the exact finished product, in the species it is sold for | The two independent trials behind a VOHC-accepted product | A statement about what that product does, in that species, in maintenance wording |
| B | A strain- or species-specific study in dogs or cats | A named probiotic strain fed to dogs in a controlled study | Education about that strain, in that species, with the grade shown; never a claim for another strain or product |
| C | Species mechanistic evidence | Studies describing how the oral microbial community of dogs shifts as gums become unhealthy | Explaining the biology; not claims about products |
| D | Laboratory (in-vitro) evidence | A strain changing how oral biofilm grows in a dish | Deciding what is worth testing; nothing about pets |
| E | Theoretical rationale | “Probiotics ought to help, because the mouth is an ecosystem” | A hypothesis, stated as one |
Results in people, in another species, from another strain, or from an ingredient tested on its own are not evidence for the pet product in front of you. We label them “not transferable” rather than grade them. Population studies, such as the Royal Veterinary College's VetCompass work, are cited with the source named in the sentence and never as evidence about a product; professional guidelines are labelled as guidance.
From grade to words: two gates
Every statement has to pass two gates. The first is evidence: is the claim supported at the right grade, for this product, in this species? The second is the law: is the wording allowed for a non-medicinal product? Passing one never excuses failing the other. The UK Advertising Standards Authority regards any stated or implied claim that a product can fix an adverse condition as a medicinal claim, unacceptable for an unlicensed product whatever evidence is held.
- Grades A and B (the product itself, or its ingredient at the same serving, tested in that species): we may use maintenance wording such as “helps reduce plaque build-up” or “helps keep tartar from building up”, with the grade shown beside the claim.
- Grade C: we explain the science with the grade beside it, and describe products by design and routine role: “designed to support a balanced oral environment”.
- Grades D and E: research language only, such as “worth testing”. No product benefit is stated.
For tools such as brushes and wipes, we describe what the tool does when used as directed: a soft brush “cleans along the gumline”.
The claims lexicon, in plain English
Our compliance lexicon sorts wording into three groups. It is built on the UK Veterinary Medicines Regulations 2013, enforced by the Veterinary Medicines Directorate (VMD), whose updated guidance of 14 January 2026 followed more than 400 enforcement reports in a year; on the UK advertising codes; and on UAE law, under which only licensed vets may practise veterinary medicine. In Great Britain a breach of the Regulations can carry an unlimited fine or up to two years' imprisonment, so we would rather be precise.
Green: wording we use
“Supports healthy gums” · “Helps maintain healthy teeth and gums” · “Helps reduce plaque build-up” · “Helps keep tartar from building up” · “Helps soften existing tartar so it is easier to remove during normal care” · “Freshens breath” · “Helps neutralise breath odours” · “Cleans along the gumline” · “Supports normal oral hygiene” · “Supports a balanced oral environment” · “Complements professional veterinary care” · “Serving”, measured by body weight · “For healthy pets”. For probiotics we go no further than “designed to support a balanced oral environment”.
Amber: only after specialist review
- “Supports oral health” anywhere near a mention of disease.
- “Tartar control”: fine as a category name, but checked for what sits beside it.
- “Microbiome balance”.
- Any statistic, which must name its source in the sentence.
- Any reference to a study, which must name the exact study, strain, species, amount and format, and never be stretched beyond them.
- Any mention of the VOHC seal, which is reserved for the exact accepted product.
Red: what we will never say, and why
- We never say a product will cure, treat, heal or prevent a disease. Only authorised veterinary medicines may make those claims; anything else is “medicinal by presentation”.
- No disease named beside a product. Education may explain what vets look for; a product description may not borrow a disease's name.
- Nothing that makes a product sound like a medicine: destroying germs, fighting infection, calming swelling, easing pain, or medicine-style measuring words. We say “serving”.
- No promises to strengthen, repair or turn back a body function. A non-medicinal product may only help maintain health in a healthy animal.
- We never write “clinically proven” without a controlled trial of that exact product, and never “vet-approved” or “vet-recommended” without documented approval.
- Nothing suggesting a product replaces the vet, a professional clean or an examination.
- No reviews that describe a health outcome. In the UK they count as our own advertising.
The VOHC seal, explained accurately
The Veterinary Oral Health Council (VOHC) seal is the best-known independent mark in pet oral care. Here is exactly what it means.
- It is earned by trials. A product needs two independent clinical trials with no animals shared between them; crossover trials need phases of at least 28 days with a 7-day washout. The VOHC reviews the trial protocol before the trials begin.
- It is narrow. The VOHC recognises two claims, helps control plaque and helps control tartar, and each needs its own evidence.
- It is product-specific. The seal belongs to one product, one claim and one species. It does not pass to other products from the same brand, or to another species.
- It is time-limited. Acceptance runs for an initial three-year term, and the council charges submission and annual fees, the amounts of which are not published.
In our range, one product carries the seal. Petsmile® Professional Pet Toothpaste, which we distribute officially, is VOHC accepted for plaque, in dogs, and has been accepted since 2011. No other product we sell carries the seal, and we will not imply that one does. The seal concerns plaque; it is not a statement about any disease. For a pet parent's guide to seals and badges, read what that little seal on the tube really means.
How every page is reviewed
Source
Every fact is drafted with its source; statistics name it in the sentence.
Grade
Scientific statements are graded A to E, naming the exact study, strain, species, amount and format.
Species
Dog evidence for dogs, cat evidence for cats, nothing borrowed from people.
Compliance
Every word, heading, image, caption and review is checked against the lexicon and each market's rules.
Sign-off
Pages show author, reviewer and dates, and are revisited when the evidence changes.
The Petdentist® Science & Compliance Office reviews everything we publish: articles, product descriptions, listings, advertisements, video scripts and the reviews we display. Pages carry a “when to see your vet” box wherever teeth, gums, breath or products are discussed, and our founder's boundary line wherever he is quoted on animal health.
Conflicts of interest
We sell oral-care products, so we have an interest in the evidence looking good. We manage that conflict in the open: by publishing this standard, by showing grades and limitations, by never borrowing evidence, by listing what we have not yet reviewed, and by recruiting an independent scientific advisory board whose members will declare their own interests. Apply the same scepticism to us that we ask you to apply to everyone else.
How to challenge a claim
If you think we have got something wrong, overstated a finding or missed a study, we want to know.
- Email [email protected] with the subject “Evidence challenge”.
- Include the page address, the sentence you are questioning and, if you have one, your source.
- We aim to acknowledge every message within one working day, and the Science & Compliance Office reviews the evidence.
- If we are wrong, we correct the page and update its date. If we disagree, we explain why.
You can also reach every team through our contact page.
How we grade evidence
Every scientific statement on this site carries a grade: A product-specific controlled trial · B strain- or species-specific study in dogs or cats · C species mechanistic evidence · D laboratory (in-vitro) evidence · E theoretical rationale. The strength of a claim never exceeds the strength of its evidence. Read our evidence standards.
When to see your vet
If you notice loose or wobbly teeth, swelling, discharge, bleeding that does not settle, reluctance to eat, dropping food, drooling, pawing at the mouth or any change in behaviour, please contact your veterinary surgeon promptly. Home care supports professional care — it never replaces it.