Veterinary Oral Health Council


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Additions to the VOHC Accepted Product List in 2019:

Canine Greenies® Aging Care Dental Chews (Tartar claim)
Canine Greenies® Puppy Dental Chews (Tartar claim)
WellPet Whimzees Brushzees and Toothbrush Treats for Dogs (Tartar claim)
ProDent PlaqueOff Powder for Dogs (Plaque and Tartar claims)


Additions to the VOHC Accepted Product List:

Healthy Advantage Oral Care for Dogs Dental Diet (Plaque and Tartar claims)
ProDent PlaqueOff Dental Bites for Dogs (Plaque and Tartar claims)
Purina DentaLife Advanced Care Chews for Dogs (Tartar claim)
Several additional flavors were added to the HealthyMouth Water Additive product line for cats.

Risk of Obstruction from Ingestion of a Dental Chew:

VOHC published a link on its website that discusses the risk of esophageal or G-I obstruction following ingestion of a dental chew. The information can be obtained by browsing to

AAHA Endorses VOHC:

The American Animal Hospital Association (AAHA) has joined the several veterinary dental organizations world-wide in endorsing the VOHC system for recognizing products that are effective in retarding accumulation of dental plaque and/or calculus.

Mechanical and Digestibility Testing:

VOHC considered whether to require mechanical or digestibility testing of dental chews and diets on its VOHC Accepted List, and decided not to require this because of the variability in determining the most appropriate tests for a particular product. VOHC encourages companies to undertake such testing during the development work on new products.


Addition to the VOHC Accepted Product List:

Whiskas DentaBites Cat Treats (Tartar claim)


Additions to the VOHC Accepted Product List:

HealthyMouth® Anti-Plaque Daily Topical Wipes for Dogs (Plaque claim)
HealthyMouth® Anti-Plaque Daily Topical Wipes for Cats (Plaque claim)
Purina DentaLife Daily Oral Care Cat Treats (Tartar claim, also marketed as Purina ProPlan Crunch Cat Snacks)
Purina DentaLife Daily Oral Care Dog Treats (Tartar claim, North American and European sizes).
Merial OraVet Dental Hygiene Chews for Dogs (Tartar claim)
Hill’s Pet Nutrition Prescription Diet Canine Dental Care Chews (Plaque and Tartar claims, also marketed as Science Diet Canine Oral Care Chews)

VOHC Trial Protocol Update:

VOHC encourages companies with a wide range of products to contact VOHC to see how best to approach trials intended to result in awarding the VOHC Accepted seal to a wide range of products.


Discussion of how to develop a reliable, objective plaque and calculus scoring system for potential use in VOHC trials started at the June 2015 European Veterinary Dental Forum, and continued at the September 2015 North American Veterinary Dental Forum. Progress in this project is described, with links to relevant resources in a VOHC webpage:

October 2014

Additions to the VOHC Accepted Product List:

HealthyMouth® Toothbrush-gel combination in dogs (Plaque claim)
Minties Dog Chews (Tartar claim)
HealthyMouth Toothbrush-gel combination in cats (Plaque claim)
Canine Greenies® Grain-free Dental Chews (Plaque and Tartar claims)

Protocol Changes:

The minimum trial period is now 28 days for both plaque and calculus trials, and a gingivitis score is to be recorded at Day 0 and end-of-trial. The policy regarding what groups must be included when a mechanical device such as a toothbrush or wipe is used to apply a chemical agent such as a tooth paste or gel has been clarified. Details are available in the Protocols section of the VOHC website (

September 2014

Product Awarded VOHC Seal

Greenies® Edible Treats for Dogs awarded the VOHC Accepted Seal for Plaque and Tartar for four sizes: Petite, Regular, Large and Jumbo.

January 2014

New Products Added to the VOHC Accepted List

Milk-Bone Brushing Chews for Dogs, manufactured by the DelMonte Corporation, has been added to the VOHC Accepted Product list in the Helps Control Tartar category. The product is available in three sizes. Canine Greenies Chews in a Hip and Joint Care formulation have been added to the VOHC Accepted Product list. Clarification Science Diet Oral Care for Dogs has met the VOHC testing standard and been awarded the VOHC Seal in the Plaque and Tartar categories. The product packaging in early 2014 does not carry the Seal because of a delay on VOHC's part in completing review of a change in the product formulation that does not affect the dental efficacy of the product.

October 2013

New Product Added to the VOHC Accepted List

Virbac CET Tartar Control Chews for Dogs, in several sizes, has been added to the VOHC Accepted Product list in the Helpd Control Tartar category. VOHC Policy Change Following the period of public comment on the proposed change in VOHC policy on Segmentation of Teeth During Scoring in VOHC Trials (see May 2013 News item), with no comments received, the policy change is now in effect.

May 2013

VOHC Policy on Segementation of Teeth during Scoring in VOHC Trials

Use of vertical segmentation will not be accepted in VOHC trials. Either whole tooth or horizontally segmented tooth surfaces can be used for scoring. Only the scores from the gingival half of the tooth are to be considered in the analysis when horizontal segmentation is used.

The specific VOHC Recommendation is:
Dogs: Score only the gingival half of all of the scored teeth.
Cats: Score only the gingival half of the canine teeth, and the whole surface of all other teeth in the VOHC set.

1. Shape and Size of Teeth of Dogs and Cats-Relevance to Studies of Plaque and Calculus Accumulation. Harvey CE: J Vet Dent 19(4); 186 -195, 2002. Summary: Crown width, height and buccal surface areas were measured on heads or skulls of four dogs and four cats, and were compared with similar measurements on models of human dentition. Buccal surface area variability was greater in dogs and cats than in humans, and teeth of cats were smaller. Horizontal (gingival and occlusal halves) and vertical (mesial, middle, and distal thirds) buccal surface area variability was also greater in canine and feline teeth compared with human teeth. This increased variability suggests the need for testing of reliability and repeatability of scoring when using plaque and calculus indices based on horizontal or vertical segmentation. Buccal surface area variability between teeth also prompts questioning the validity of equal weighting of smaller, irregularly-shaped teeth when calculating a mean mouth score. Whether equal or more reliable results would be obtained from scores of whole teeth in comparison with segmentation indices used currently has yet to be determined.

2. Evaluation of the Logan and Boyce Plaque Index for the Study of Dental Plaque Accumulation in Dogs. Hennet P, Servet E, Salesse H, Soulard Y: Res Vet Sci, 80, 175-180, 2006. Summary: The objectives of this study were to assess intra-examiner (experienced examiner) and inter-examiner agreements (experienced versus non-experienced examiners) of scores assessed with the Logan & Boyce plaque index and to evaluate whether a modification of this index, where anatomical landmarks are used for horizontal division [mod L&B-AL] and dye references are used for assessing intensity of dye (plaque thickness) [mod L&B-DR], would improve repeatability. The Logan & Boyce index was found to be inaccurate when scoring plaque coverage as it underestimated the total crown surface. The contribution of the gingival part to the total tooth score was minimized by the Logan & Boyce index compared to the mod L&B-AL/DR. Precision of global plaque scorings was significantly improved by the mod L&B-AL/DR. Intra-examiner agreement of plaque thickness and plaque coverage scorings on the gingival part of the tooth was significantly improved by the mod L&B-AL/DR. Studies evaluating plaque accumulation in dogs should therefore use the mod L&B-AL/DR rather than the Logan & Boyce index.

Brushing Policy for Cats

VOHC Trials Involving Tooth Brushing in Cats

What Brush to Use in Cats:
Because the mouths of cats are too small for use of most standard-sized human tooth brushes, a brush marketed for use in cats can be used. 'Finger-brushes" (small brushes that are mounted on a cover placed over a finger) are not to be used as the control brush in VOHC trials. The trial sponsor is to select a small head, soft bristle brush; the selection will be reviewed by VOHC during the required pre-trial protocol review. Once a particular brush has been shown to meet or exceed the VOHC standard in dental effectiveness, this will be adopted as a VOHC 'control brush'; subsequently, novel brushes can be submitted for VOHC review if trial data show that they are statistically 'at least as good as' the VOHC control brush in dental efficacy and provided that the trial demonstrates that the test brush does not injure oral soft tissues.

Brushing Strokes for Cats:
For VOHC trials, the following sequence is to be used, to ensure consistency between trials.

  • Conditioning the cats pre-trial to accept brushing is recommended.
  • Recommended method for restraining cats while the teeth are brushed: Place the cat on the operators lap with the cat's hind-quarters facing the abdomen and with your arms acting as gentle 'side bars'. For a right-handed individual, the palm of the left hand is placed on the top of the head of the cat, with the middle finger and thumb placed on the side of the face to retract the commissures of the lips. This exposes the canine and premolar teeth on each side of the mouth. The little finger of the hand holding the brush can be placed below and between the mandibles to control movement of both jaws. The brush, held in the right hand, is laid against the teeth and stroked horizontally as described below. Initially during the conditioning period, very light brushing pressure is used, increasing the pressure each time until the bristles just start to curve.
  • To assist in restraint, and to provide more consistency in the application of the brush, the cat's mouth is to be gently held closed.
  • The brush is to be applied to the surface of the teeth at a 45o angle, with the tips of the bristles pointed towards the gingival tissue of the upper jaw teeth. The head of the brush is to be wide enough so that the lower layers of bristles will brush the teeth in the lower jaw during each horizontal brush stroke.
  • The brush is pressed gently against the surface of the teeth during the brush stroke - if the bristles visibly deflect (curve), the pressure applied is too high.
  • Three horizontal strokes, each consisting of a back and forth movement across the dental arcade, are made on each side. No attempt is made to brush the interior (palatal or lingual surfaces) of the teeth – in cats, dental plaque and tartar accumulate most rapidly on the buccal surfaces of the teeth.
  • Each horizontal stroke is to include the canine and premolar teeth in the upper jaw and canine, premolar and molar teeth in the lower jaw.

Assignment to groups:
Cats will vary in their willingness to allow their teeth to be brushed. A pre-trial conditioning exercise (see above) is recommended to identify as many cats as possible as being 'willing' to have their teeth brushed. When the total number of cats potentially available for a brushing study is insufficient to permit only cats willing to have their teeth brushed to be randomly assigned to either brushing and control groups, cats in the 'willing' group can be assigned to the brushing group(s) and 'unwilling' cats can be assigned to the non-brushed group(s).

Palatability agents:
Although doing so may increase the number of cats that are 'willing' to have their teeth brushed, palatability agents applied to the brush are not to be used in trials designed to test the effectiveness of a brush or similar device, because the palatability agent may predispose to accumulation of plaque.

Pre-trial Screening Examination for Cats in VOHC Trials:
(This would apply to all VOHC trials using cats)
Cats often have tooth resorption, sometimes in multiple teeth. When this is present and open to the oral environment, gingival inflammation and pain are common. Cats with tooth resorption at the gingival margin are not suitable for VOHC trails because they are likely to be more painful than cats without such lesions.

Cats are to be pre-screened by an awake oral examination consisting of visual inspection of the buccal surfaces of the teeth required to be scored in a VOHC trial (upper C, P3, P4, lower C, P3, P4, M1) - the teeth are not touched with an instrument during the inspection.

Any cats with the following findings are to be excluded from the pool for assignment to one of the trial groups:

  1. Severely inflamed gingiva (bright red, rough surfaced, may be spontaneously bleeding) anywhere along the buccal gingival margin of scored teeth.
  2. A focused lesion of inflamed gingiva of the sort often associated with an area of tooth resorption at the gingival margin of a particular tooth.
  3. Evidence of loss of attachment, seen as exposure of part of the root. Presence of plaque and tartar on the crown of the teeth is not of itself reason to exclude the cat, as this will be removed during the pre-trial professional dental cleaning procedure.

November 2011

New Products added to the VOHC Accepted List

Several new products were added to the VOHC Accepted Seal list. They are:

ESSENTIAL healthymouth Water additive with mobility health formulation (plaque claim).

ESSENTIAL healthymouth Anti-plaque topical spray (plaque claim).

Royal Canin Feline Dental Diet (plaque claim). This product will be launched to the market in 2012 (tentative launch date September).

Supersmile toothpaste for dogs (plaque claim). This product will be launched to the market in 2012 (exact date not know at time of this listing).

ESSENTIAL healthymouth Anti-plaque topical spray (plaque claim).

SANOS Dental sealant, for application to the clean surface of teeth at the end of a professional scaling procedure (plaque and tartar claims).

May 2011
On the unanimous recommendation from Council, the AVDC Board approved a 'VOHC Policy on Trials Involving Use of Brushes or Similar Mechanical Devices'. Click VOHC Brushing to view the full VOHC brushing policy document.

April 2011

Three new products have been added to the VOHC Accepted Product list. They are:

ESSENTIAL healthymouth anti-plaque gel

ESSENTIAL healthymouth anti-plaque water additive

ESSENTIAL healthymouth anti-plaque gel

These products are marketed by HealthyMouth, LLC.

Protocol changes:

Protocol Change:
Pre-Trial Protocol Review VOHC requires pre-trial protocol review, to ensure that trials will be conducted in compliance with VOHC requirements. Pre-trial protocol review is designed to avoid potentially costly mistakes in how VOHC trials are conducted. This policy is in effect for all submissions received after January 1st, 2012. Pre-trial review for submissions received prior to January 1st, 2012 is very strongly encouraged; however, VOHC recognizes that some submissions that it may receive in calendar 2011 may be based on trials that were underway before the pre-trial protocol review requirement was adopted by VOHC. Pre-trial protocol review is provided as a free, confidential service by VOHC. Send the proposed protocol to A response to a request for pre-trial review will be provided by VOHC within two weeks of receiving the request.

Protocol Change:
Anesthesia and Intubation During Dental Scaling To ensure that the required "clean-tooth model" is safely used in trials conducted under the VOHC protocol, animals whose teeth are scaled at day zero of a trial are to be anesthetized and the trachea is to be intubated during the scaling procedure.

Protocol Change:
Use of Client-Owned Animals in VOHC Trials An information/informed consent document ('Owner document') is to be signed by the owners before entry of the subject into the trial. A blank copy of the Owner document is to be included in the submission. The Owner document is to include a requirement that the owners complete a daily compliance log, and copies of the completed owner's daily compliance logs are to be included in the submission. Out-of-protocol events reported by the owners are to be described and comments by the sponsor on significance of the out-of-protocol events are to be provided in the submission.

December 2010

Two products that are no longer marketed have been removed from the VOHC Accepted list. They are:

Friskies Feline Dental Diet and Del Monte Tartar Check Biscuits for Dogs

Change in VOHC Standard

The Board of Directors of the American Veterinary Dental College approved a recommendation from the Veterinary Oral Health Council to change the standard required for awarding the VOHC Accepted Seal.

This change is effective from January 1st, 2011.

Purpose of the Change:
Eliminate the difference between the VOHC chemical and non-chemical plaque standards and bring the calculus (tartar) claim standard into line with the plaque claim standard by adopting the current American Dental Association standard, whether the dental effectiveness is achieved mechanically or chemically.

New VOHC standard, as of January 1st, 2011:
The VOHC standard for required minimum reduction in plaque and/or calculus in the product group compared with the control group is 15% (minimum in each of the two trials) and 20% (minimum mean of both trials), with each trial having a statistically significant difference between the control and product groups.

Reduction (VOHC efficacy %) is defined as:

([Control group mouth mean] minus [Test group mouth mean]) divided by (Control group mouth mean) x 100

Impact on products that currently carry the VOHC Accepted Seal:
Products that currently carry the VOHC Seal but for which the trial data submitted to VOHC do not meet the new standard will grand-fathered (permitted to use the VOHC Accepted Seal) for five years following the date on which the change becomes effective (January 1st, 2011).

September 2008
Healthymouth, an anti-plaque water additive, has been added to the VOHC accepted list in the Plaque claim category for dogs.

May 2008
The Board of Directors of AVDC accepted a recommendation from Council to add the following statement to the Safety and Regulatory Issues statement at the bottom of the Protocol page:

'Safety ' in the VOHC context includes:

A. Major extra-oral or body-wide issues such as toxicity, esophageal or gastro-intestinal obstruction or perforation, or gross nutritional imbalance;

B. Trauma to oral tissues, such as fracture of teeth or laceration or penetration of oral mucosa.

Complaints from consumers that relate to any of the product safety issues mentioned above are to be promptly copied to VOHC, and annual confirmation of continuation of use of the VOHC Accepted Seal is contingent on affirmation that no safety complaints that have not already been brought to VOHC's attention have been received by the product sponsor.

February 2008
VOHC Accepted Seal awarded to Vetradent's Baby Bluechews and dc TinyToy Dental Chews in the Tartar claim category. VOHC Accepted Seal awarded to Diamond Food's Bright Bites and Checkups Dog Treats, all sizes, in the Plaque and Tartar claim categories.

January 2008
VOHC Accepted Seal awarded to Canine Greenies Senior and Canine Greenies Lite dog treats, all sizes, in the Plaque and Tartar claim categories.

December 2007
Dogs do love to chew...... World series ball eaten by dog Thurs., Dec. 20, 2007 BOSTON - The World Series ball is gone, and Jonathan Papelbon has an excuse: My dog ate it. Farfetched or not, that's what the Red Sox closer insists happened to the souvenir from the final out of Boston's sweep this year. Really, Papelbon blamed it on his bulldog, Boss. "He plays with baseballs like they are his toys," Papelbon told the Hattiesburg (Miss.) American. "He jumped up one day on the counter and snatched it. He likes rawhide. He tore that thing to pieces. I'll keep what's left of it."

October 2007

New Canine Greenies Treat is awarded the VOHC Seal of Acceptance for Plaque and Tartar. New Canine Greenies is available in five sizes.

Tartar Shield Soft Rawhide Chews is awarded the VOHC Seal of Acceptance for Tartar. Tartar Shield Chews are available in five sizes.

Feline Greenies has been removed from the VOHC Accepted list because the manufacturers have changed the formulation, and the old formulation is no longer in stock at point-of-purchase.

VOHC Council approved use of the Gingival Contour Plaque Index scoring system ( described by Scherl et al in the March 2007 issue of the Journal of Veterinary Dentistry), provided that the plaque score and calculus score in each dog on day 0 of the trial is zero. In a related item, VOHC changed the minimum seven day trial period for plaque by adding: unless a scoring method validating a shorter period has been previously approved by Council.

January 2007
The Canine Greenies formulation that was awarded the VOHC Accepted Seal in 2004 has been withdrawn from the market, and the listing for Canine Greenies has been removed from the VOHC Accepted list.

October 2006

Upon the recommendation of VOHC Council, the AVDC Board of Directors has ratified changes in protocols:

Clarified wording on use of segments of teeth when scoring.

Adopted a safety requirement for chemical agents included as plaque or tartar inhibitors.

Eliminated the need for three arm/leg trials when evaluating products with both mechanical and chemical effects.

Adopted specific information on statistical analysis procedures.

The changes are incorporated in the documents currently available on the VOHC web site.

September 2006
Vetradent Dog Chews, manufactured by Vetradent Inc. awarded the VOHC Seal of Acceptance for Plaque and Tartar.

August 2006
Feline Greenies, manufactured by S&M Nu-Tec, Inc, awarded the VOHC Seal of Acceptance for Tartar.

July 2006
Nestle Purina PVD (Dental Health) Diets awarded the VOHC Accepted Seal for Feline Formula (Plaque and Tartar) and Small Bites and Regular Size Canine Formula (Tartar).

May 2005
Hartz® Flavor Infused Oral Chews awarded the VOHC Accepted Seal for Plaque and Tartar for two sizes: Large Dogs and Small Dogs Sizes.

January 2005
Greenies® Edible Treats for Dogs awarded the VOHC Accepted Seal for Plaque and Tartar for the Teenies size.

February 2004

A correction was made in the VOHC criteria for testing products of different size in dogs. Click Product Line and then scroll down to the Differences in Size of Product section to read the corrected policy.

Today is the start of National Pet Dental Health Month in North America (NPDHM), and to help celebrate this important yearly milestone in the oral and general health of North American companion animals, VOHC launched its revised and updated web-site, which now includes consumer information on periodontal disease in cats and dogs. To find out more about National Pet Dental Health Month, click NPDHM.

Additions to the list of Organizations Recognizing VOHC

VOHC is also celebrating the recent addition of the American Veterinary Dental Society and the Academy of Veterinary Dentistry to the list of dental organizations that endorse the VOHC Seal of Acceptance system. The VOHC Seal system is now recognized on four continents (Asia, Australasia, Europe and North America). For a full list of the organizations who are on-board with VOHC, click World-Wide.

Changes in Council

Two Members rotate off: Two dental scientists who were critical in establishing the Veterinary Oral Health Council in 1997 and were original members of the Council have rotated off the Council.

Drs. John Hefferren and George Stookey brought to the VOHC discussions and decisions many years of experience in efficacy recognition from the human dental arena. The immense contributions that Drs. Hefferren and Stookey made in building credibility and avoiding pot-holes in VOHC's early years are very much appreciated by VOHC Director Colin Harvey and by the Board of Directors of the American Veterinary Dental College, which administers the VOHC.

New Members:
Recognizing the international reach of the VOHC system, the Board of Directors of the American Veterinary Dental College appointed Drs. Marco Gioso (Sao Paulo, Brazil) and Philippe Hennet (Paris, France) to the Council for three-year terms, effective January 1, 2004. The Council now consists of ten Diplomates of the American Veterinary Dental College. For a full list of Council members and a brief description of what Council members do, click Council.

Changes in Protocols and Fees

The revised web site contains an enlarged and updated series of documents on VOHC protocols and submission procedures for companies marketing products that may qualify to carry the VOHC Seal of Acceptance.

In addition to web site changes designed to make the VOHC protocols and related requirements clearer and easier to access, some changes in content have been made in the VOHC protocols:

  1. A category for tooth-brushes and similar mechanical aids designed to be used by pet owners has been added to the protocol document (see "Mechanical Protocols").
  2. The body-weight section of the "Product Line" document has been revised to make identification of dogs for inclusion in trials involving defined body weight groups more practical (see "Differences in Size of Product and in Body Size Classes of Dogs" on the "Product Line" page).
  3. The Submission Fees have been revised.
    1. The requirement for a separate fee for each claim (plaque or calculus) has been eliminated. A single fee now is payable for a submission for either or both claims. Since most past submissions have included review of trials of products for both claims, the effect of the revised fee structure is to maintain or reduce the submission fee for review of plaque and (tartar) calculus claims for a single product.
    2. Fees for products applied by owners, such as brushes, have a separate, lower fee structure.
    3. The standard fee now covers use of the VOHC Seal world-wide, and a separate fee structure has been established for submissions on behalf of products that are marketed only in one country.
    4. A fee structure for multiple products in a 'Product Line' has been established.

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