Evaluation of a topical gel containing a novel combination of essential oils and antioxidants for reducing oral malodor in dogs

Am J Vet Res. 2014 Jul;75(7):653-7. doi: 10.2460/ajvr.75.7.653.


Objective: To evaluate the effectiveness of a topically applied gel containing essential oils (menthol and thymol) and polyphenolic antioxidants (phloretin and ferulic acid) for reducing halitosis in dogs.

Animals: 20 dogs.

Procedures: A blinded crossover clinical trial was conducted. Dogs received a dental cleaning and examination (periodontal examination including periodontal probing and assessments of plaque, calculus, and gingivitis). Owners then applied a gel (active or placebo) to oral soft tissues twice daily for a 4-week period. Teeth of the dogs were cleaned again, and owners applied the other gel for a 4-week period. Clinicians scored halitosis immediately after the initial cleaning and at 4 and 8 weeks, and owners scored halitosis weekly.

Results: Halitosis assessment by clinicians revealed that both groups had improvement in halitosis scores. Two dogs were removed because of owner noncompliance. In the active-to-placebo group (n = 9), halitosis was significantly reduced during application of the active gel but increased during application of the placebo. Seven of 9 owners reported increased halitosis when treatment was changed from the active gel to the placebo. In the placebo-to-active group (n = 9), halitosis decreased during application of the placebo and continued to decrease during application of the active gel. Seven of 9 owners reported a decrease in halitosis with the active gel.

Conclusions and clinical relevance: An oral topically applied gel with essential oils and polyphenolic antioxidants applied daily after an initial professional dental cleaning decreased oral malodor in dogs.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Topical
  • Animals
  • Anti-Inflammatory Agents / therapeutic use
  • Antioxidants / therapeutic use*
  • Coumaric Acids / therapeutic use
  • Cross-Over Studies
  • Dental Plaque / complications
  • Dental Plaque / veterinary
  • Dog Diseases / drug therapy*
  • Dog Diseases / etiology
  • Dogs
  • Female
  • Gels
  • Gingivitis / complications
  • Gingivitis / veterinary
  • Halitosis / drug therapy
  • Halitosis / etiology
  • Halitosis / veterinary*
  • Male
  • Menthol / therapeutic use
  • Oils, Volatile / therapeutic use*
  • Phloretin / therapeutic use
  • Thymol / therapeutic use


  • Anti-Inflammatory Agents
  • Antioxidants
  • Coumaric Acids
  • Gels
  • Oils, Volatile
  • Menthol
  • Thymol
  • ferulic acid
  • Phloretin