Open Wide! Unique insights from the mouths of Yorkshire terriers

Dr. Lucy Holcombe leads the Oral Health research programme at Waltham Petcare Science Institute. In her role she works with other scientists to investigate the role of biomarkers in pet health and disease. Her primary focus for several years has been unravelling the intricacies of oral health problems in dogs and cats. She's intrigued by what drives a switch from health to disease and it’s a topic she's followed throughout her career, from her plant pathology Ph.D., through academic research in human disease to the world of pet healthcare today. Here she shares her perspective on our latest oral health research in small dog breeds, as well as some actionable tips to encourage healthy mouths. 

Gum disease and shark teeth!

For most veterinary professionals it won't be any surprise to hear our research has shown that Yorkshire terriers are particularly prone to oral health issues. They are a breed that has a high incidence of gum disease (periodontal disease) and are frequently found to need significant dental treatment in clinic. For me, having the opportunity to conduct in depth research into the oral health of this extra-small breed alongside my colleagues at Waltham has been more revealing, and scientifically fascinating, than I ever imagined.  

I can clearly remember one of our first litters of Yorkshire terrier puppies coming into the office on a socialisation visit. As we sat having playtime on the floor, these tiny balls of energy were into everything, enthusiastically exploring the world with their mouths! Observing them it was evident that there wasn’t a lot of space in their little mouths for teeth to grow into, and it was not long before problems started to manifest. We found that many of the puppies developed what looked like ‘shark teeth’ - two rows where the juvenile and adult teeth were present at the same time aka persistent deciduous teeth (PDT). 

They required careful veterinary monitoring between two and seven months of age and sometimes intervention, such as extraction of juvenile teeth or ball therapy, to prevent future misalignment of the teeth and soft tissue damage. The canine teeth were the most frequently retained:12% were retained in dogs >5 kg, although interestingly this varied with bodyweight, rising to over 89% in dogs ≤3kg. It’s thought that toy and small breed dogs are particularly prone to PDT and periodontal disease because of more crowded adult dentition than larger breeds, something that is likely a result of genetic factors. 

Hot off the press! – Our latest insights from Yorkshire terriers  

Two new papers in BMC Vet Research describe our latest research into Yorkshire terrier oral health. In the first study we analysed the plaque microbiota, the communities of bacteria within the sticky dental plaque that accumulates on teeth. While it was already known that distinct bacterial profiles are associated with healthy gingiva and periodontal disease, the opportunity to run a single breed study looking at periodontal disease and bacterial profiles in Yorkshire terriers from the moment adult teeth appeared through to 18 months of age was an opportunity not to be missed. 

For those who like to know about bacterial names, healthy gingiva were associated with Proteobacteria (e.g., Moraxella and Pasteurellaceae) with a higher representations of Firmicutes (e.g. Peptostreptococcaceae), Spirochaetes (e.g. Treponema) and Synergistetes in periodontitis.  

Through the second study we found that dry diets tended to keep the microbiota in a more health-associated profile than wet diets, most likely due to the mechanical abrasion of chewing the kibbles, although this wasn't accompanied by a statistically significant improvement in periodontal health. Knowing more about the bacterial changes in the early stages of periodontal disease can help us develop tools to improve disease diagnosis, drive awareness and support recommendations for effective preventative and management strategies. 

Bitesize tips for healthy mouths in Yorkshire terriers (and other dogs)

For Yorkshire terriers and other extra-small and small breed dogs that are particularly susceptible to PDT and periodontitis it’s critical to monitor from a very early age. Here are some top tips for veterinary professionals to manage the mouths of small breeds:

• During a puppy’s first few visits look out for signs of persistent deciduous teeth and be ready to intervene
• Talk to owners about the elevated risks of periodontal disease in small and extra-small dogs. This is a handy tool we’ve developed for understanding breed-based risk
• Advise on the importance of prophylactic homecare strategies to help prevent gum disease. Explore what options might be both realistic and practical for the individual dog and its owner.
• Share practical tips to get a toothbrushing routine in place. Try these guides.

Keeping on top of oral health is important for our canine companions, just like it is for us. Doing so not only minimises the chance of future dental complications but increasing evidence suggests it also promotes overall health and wellbeing.  

I remain amazed at how much we learnt from our small but mighty Yorkshire terrier puppies, and I hope the insights from our oral health research, and that of other groups, will provide veterinary professionals and owners with new approaches to help step-change oral care for dogs.