A new study conducted by Mars Petcare and published in The Veterinary Journal has shown that smaller breeds of dogs, such as Dachshunds and Toy Poodles, are generally more predisposed to periodontal disease than larger breeds, such as German Shepherds and Boxers1

For the study, researchers reviewed more than three million medical records from Banfield Pet Hospital across 60 breeds of dogs in the United States, finding that periodontal disease (both gingivitis and periodontitis) occurred in 18.2% of dogs overall (517,113 cases).

The authors say that while the true prevalence of periodontal disease (44-100% of cases) is only realised through in-depth clinical investigation, the figure reported in this study was consistent with other research based on conscious oral examinations.

When the authors reviewed the data by dog size, they found that extra-small breeds (<6.5 kg/14.3 lbs) were up to five times more likely to be diagnosed with periodontal disease than giant breeds (>25 kg/55 lbs)(P <0.0001).

Additional risk factors for periodontal disease seen in the study included a dog’s age, being overweight and time since last scale and polish.

Dr Corrin Wallis, Microbiome Workstream Leader at the Waltham Petcare Science Institute said: "This is not the first study suggesting that smaller dogs are more likely to have dental problems than larger dogs, but many of the earlier studies looked at a relatively small number of dogs". 

The five breeds with the highest prevalence of periodontal disease found in the study were the large Greyhound (38.7%), the medium-small Shetland Sheepdog (30.6%), and the extra-small Papillon (29.7%), Toy Poodle (28.9%), and Miniature Poodle (28.2%). Giant breed dogs (such as the Great Dane and Saint Bernard) were among the lowest breed prevalence estimates. 

The authors say there are several potential reasons why smaller dogs are more likely to develop dental issues than larger dogs. For example, smaller dogs may have proportionally larger teeth, which can lead to tooth overcrowding and increased build-up of plaque leading to inflammation of gums. Smaller dogs also have less alveolar bone (the bone that contains tooth sockets) compared to their relatively large teeth.

Corrin added: "Regardless of the reasons that smaller dogs have increased risk for periodontal disease, knowing the true magnitude of the risk across breeds is an important step in providing quality care for all dogs, both in the veterinarian’s office and at home.


  1. C. Wallis, E.K. Saito, C. Salt, L.J. Holcombe, N.G. Desforges, Association of periodontal disease with breed size, breed, weight, and age in pure-bred client-owned dogs in the United States, The Veterinary Journal, Volume 275,
    2021, 105717, ISSN 1090-0233, https://doi.org/10.1016/j.tvjl.2021.105717(https://www.sciencedirect.com/science/article/pii/S109002332100112X)

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