Oral Disease & The Pet Microbiome

Oral Disease & The Pet Microbiome

In This Article

Dental disease is one of the most prevalent medical conditions veterinarians encounter. According to the American Veterinary Medical Association (AVMA), the majority of dogs and cats will have some level of dental disease by age three. (1) Unless proactive measures are taken, dental diseases will worsen with time. 

Signs of Decay

When it comes to dental disease, our pets are great at hiding signs of discomfort. Common signs of dental disease in our companion animals can include difficulty or abnormal chewing, drooling, or dropping of food when eating, bleeding along the gums, discolored teeth, reluctance to eat, tartar, or halitosis (i.e., bad breath). Some of the most common dental abnormalities seen in dogs are fractured teeth, usually from chewing on hard objects, and periodontal disease which is inflammation along the gingiva that results from plaque accumulation which contains bacteria. Eventually if left alone, this will turn into tartar. In addition to periodontal disease, our feline friends also suffer from resorptive lesions. A resorptive lesion is a small erosion on the tooth that eventually progresses to the point that the entire tooth is destroyed exposing the nerve itself. As you can imagine, this can be quite painful, and unfortunately, the cause is still unknown.


Predontial Pathogens in the Gut

Inflammation from periodontal disease can result in bacteria entering the bloodstream which can affect the liver, kidneys, cardiac, and pulmonary functions. The oral cavity and gut microbiome are both very large microbial habitats that are separated by an oral gut barrier, physical distance, and chemical differences. (2) In an otherwise healthy animal, bacteria from the oral cavity do not tend to take up residence in the gut. However, in cases where an animal is compromised with a systemic disease or severe periodontal disease, sometimes the oral bacteria can travel and reside in the GI tract. In studies with mice, researchers examined the common periodontal pathogen P. gingivalis. This bacteria was administered to mice in a few different studies which concluded that P. gingivalis did alter the GI microbiome and secondarily the mechanical and immune barrier functions of the intestines. Mice that were administered P. gingivalis had increased levels of endotoxemia which was likely a result of the alteration of the intestinal barrier. (3)


Preventative Care Option

While dental disease may be difficult to prevent, there are some techniques you can employ at home to aid in prevention. Brushing your pet’s teeth with a recommended pet-friendly toothpaste can help prevent plaque build-up. This is most effective if performed daily. If your pet will not allow you to brush their teeth, the incorporation of dental chews or dental diets can also help prevent plaque build. These products are specifically designed to encourage more chewing which helps remove plaque. A review was performed to examine the benefits of probiotics in the treatment or prevention of periodontal disease.

It examined several studies with both human and animal models and determined that some studies revealed that there was less gingival inflammation, decreased periodontal pockets, and reduced periodontal pathogens in the subjects administered probiotics. (4) There is still very limited research available on probiotics and their impact on oral health, but it appears there may be some potential for their use to combat dental disease in the future. 



  • Hobby, Gerren, et al. “Chronic Kidney Disease and the Gut Microbiome.” American Journal of Physiology, 2019, pp. FI211–17. PubMed, doi:10.1152/ajprenal.00298.2018.
  • Graboski, Amanda L, et al. “Gut-Derived Protein-Bound Uremic Toxins.” Toxins, vol. 12, no. 9, 2020, p. 590. PubMed, doi:10.3390/toxins12090590.
  • Lippi, Ilaria, et al. “Effects of Probiotic VSL#3 on Glomerular Filtration Rate in Dogs Affected by Chronic Kidney Disease: A Pilot Study.” The Canadian Veterinary Journal, 2017, pp. 1301–05. PubMed, pubmed.ncbi.nlm.nih.gov/29203940.
  • Wang, Xifan, et al. “Aberrant Gut Microbiota Alters Host Metabolome and Impacts Renal Failure in Humans and Rodents.” Gut, vol. 69, no. 12, 2020, pp. 2131–42. Crossref, doi:10.1136/gutjnl-2019-319766.
Author's Name

Dr. Dana Hogg

Dr. Dana Hogg graduated in 2015 from North Carolina State University. She grew up in Wilson, North Carolina. Growing up with several animals, Dr. Hogg was drawn to the field of veterinary medicine at a young age. She completed her undergraduate degree at NCSU in 2009 and her master's degree in 2011.